Well as promised, I'm going to start a series of DIY's, so heres the first
Sorry for the fuzzy pics, they've been saturated because of me resizing/editing them. I will fix them, I just don't have time right now.
This was done on a 2005 Jetta BBW, but applies to AZG, AVH, or BEV engines as well
The AEG process is similar, but uses a different coil pack. I'm sure you can figure it out, once you look at it.
Symptoms of a bad coil pack
Well what was happening for me, was that my car was misfiring on cold starts. Chances are, if your car is only misfiring in wet or cold weather, the coil pack is bad.
Here is a picture of why mine was bad. There was cracks in the plastic, over the cylinder 3 coil.

There is a very simple way to test your coil pack.
Testing
Get a spray bottle, fill it with water.
Go outside, start your car.
Pop your hood, and spray your coil pack.
If it misfires, its bad.
If you do this process at night, you'll probably be able to see an electrical "arc"
Temporary Fix
So you can still drive your car while you're saving for a new one, or waiting for one in the mail, Coat the coil pack in WD40. I mean really drench the thing. If you can visually see any cracks, or you saw an arc and where its coming from - make sure you really spray that area. The WD40 reduces moisture and displaces water. Wait a couple hours to let it dry, then come out and start your car. It should be running normal
What tools you'll need
- 5mm + 6mm allen keys, hex bits, or pressed in hex bit sockets.
- Your average, any size wrench for a cheater bar (if you're using Allen keys)
I prefer to use my 12v bosch electric impact on small jobs like this. Its small, cordless, powerful, and fast.

Replacement
To start, its probably a good idea to disconnect the battery ground. Probably not nessecary, but I do it just about anytime I'm working in the engine bay. Its easy, and I'd rather do it and not need to, than need to and not do it.
Also go ahead and pull your engine cover off
Next, you need to get your secondary air pump out of the way. Disconnect the two hoses on the top of your pump, and then remove the Three (3) 6mm Hex bolts connecting the Bracket to the intake manifold (Circled in Blue). You cannot see one of them in the picture, but just follow the bracket towards the middle of the car, and you'll find it.
You do not need to unbolt the pump from the bracket, or disconnect the electrical connector connector. just move it out of the way to the left.
Do not attempt to use any Standard size hex bit or allen key. You will most likely strip it. Standard sizes are either too big or too small, just do it right and use metric bits or keys.
(Circled in Purple) Be careful when working with your secondary air pump. There is rubber bumpers that connect the pump to the bracket, and they can become very brittle. As you can see in the picture, mine are cracked and dry rotted. I'm about to replace mine as well.

Next, You're left with the coil pack exposed. Its easier if you leave the electrical connector for the coil pack on it, until you get it unbolted and out of there. Its then much easier to wiggle off. BUT, you'll want to disconnect the harness for the wires, its right in front of the bottom of the coil pack (circled in green).

Try to wiggle the spark plug wires off of the coil pack. This can be difficult, but try not to spin them too much, you don't want to screw your wires. and this will happen to you

Once you get all four wires off, you'll want to unscrew the Three (3) 5mm Hex bolts , now's also a good time to inspect the coil pack end of your spark plug wires. Check for dry rotting, cracks, cuts, etc. take note of anything you see, because if you have any problems with misfires after replacing your coil pack, and you check the obd or vagcom, this will help you narrow down the problem.

If you're using an allen key, these bolts can be difficult to break loose. If you don't already know this trick, go ahead and do this. It will give you more space and leverage so you can break it slowly and easily, and not bang up your knuckles.

From there, just unhook the electrical connector on the coil pack, and reassemble in reverse! Make sure you connect the spark plug wires in the correct order, as noted above, and Do your best not to strip the bolts supporting the pump bracket, sometimes they'll want to go in a little crooked.
Start her up and take her for a spin!
Happy wrenching!

^Dirty Gerty haha^
(If you can't tell I live on a farm)
Sorry for the fuzzy pics, they've been saturated because of me resizing/editing them. I will fix them, I just don't have time right now.
This was done on a 2005 Jetta BBW, but applies to AZG, AVH, or BEV engines as well
The AEG process is similar, but uses a different coil pack. I'm sure you can figure it out, once you look at it.
Symptoms of a bad coil pack
Well what was happening for me, was that my car was misfiring on cold starts. Chances are, if your car is only misfiring in wet or cold weather, the coil pack is bad.
Here is a picture of why mine was bad. There was cracks in the plastic, over the cylinder 3 coil.

There is a very simple way to test your coil pack.
Testing
Get a spray bottle, fill it with water.
Go outside, start your car.
Pop your hood, and spray your coil pack.
If it misfires, its bad.
If you do this process at night, you'll probably be able to see an electrical "arc"
Temporary Fix
So you can still drive your car while you're saving for a new one, or waiting for one in the mail, Coat the coil pack in WD40. I mean really drench the thing. If you can visually see any cracks, or you saw an arc and where its coming from - make sure you really spray that area. The WD40 reduces moisture and displaces water. Wait a couple hours to let it dry, then come out and start your car. It should be running normal
What tools you'll need
- 5mm + 6mm allen keys, hex bits, or pressed in hex bit sockets.
- Your average, any size wrench for a cheater bar (if you're using Allen keys)
I prefer to use my 12v bosch electric impact on small jobs like this. Its small, cordless, powerful, and fast.

Replacement
To start, its probably a good idea to disconnect the battery ground. Probably not nessecary, but I do it just about anytime I'm working in the engine bay. Its easy, and I'd rather do it and not need to, than need to and not do it.
Also go ahead and pull your engine cover off
Next, you need to get your secondary air pump out of the way. Disconnect the two hoses on the top of your pump, and then remove the Three (3) 6mm Hex bolts connecting the Bracket to the intake manifold (Circled in Blue). You cannot see one of them in the picture, but just follow the bracket towards the middle of the car, and you'll find it.
You do not need to unbolt the pump from the bracket, or disconnect the electrical connector connector. just move it out of the way to the left.
Do not attempt to use any Standard size hex bit or allen key. You will most likely strip it. Standard sizes are either too big or too small, just do it right and use metric bits or keys.
(Circled in Purple) Be careful when working with your secondary air pump. There is rubber bumpers that connect the pump to the bracket, and they can become very brittle. As you can see in the picture, mine are cracked and dry rotted. I'm about to replace mine as well.

Next, You're left with the coil pack exposed. Its easier if you leave the electrical connector for the coil pack on it, until you get it unbolted and out of there. Its then much easier to wiggle off. BUT, you'll want to disconnect the harness for the wires, its right in front of the bottom of the coil pack (circled in green).

Try to wiggle the spark plug wires off of the coil pack. This can be difficult, but try not to spin them too much, you don't want to screw your wires. and this will happen to you

Once you get all four wires off, you'll want to unscrew the Three (3) 5mm Hex bolts , now's also a good time to inspect the coil pack end of your spark plug wires. Check for dry rotting, cracks, cuts, etc. take note of anything you see, because if you have any problems with misfires after replacing your coil pack, and you check the obd or vagcom, this will help you narrow down the problem.

If you're using an allen key, these bolts can be difficult to break loose. If you don't already know this trick, go ahead and do this. It will give you more space and leverage so you can break it slowly and easily, and not bang up your knuckles.

From there, just unhook the electrical connector on the coil pack, and reassemble in reverse! Make sure you connect the spark plug wires in the correct order, as noted above, and Do your best not to strip the bolts supporting the pump bracket, sometimes they'll want to go in a little crooked.
Start her up and take her for a spin!
Happy wrenching!

^Dirty Gerty haha^
(If you can't tell I live on a farm)