The fans are an easy job. Basically, you remove the belly pan, disconnect the connector, remove four T30 screws and the assembly comes out the bottom. The FCP Euro suggestion is good. I would take care of that ASAP as overheating is a sure way to destroy an engine.
The turbo failure is also unfortunately common. It is almost always the result of a worn waste gate actuator linkage, which allow exhaust gasses to bypass the turbine wheel. This sets a P0299 underboost fault and the resultant reduction in performance. This is not a catastrophic failure and can wait. I would highly recommend getting the Borg Warner replacement rather than the OEM IHI. While it won't save you money, it will likely last longer than the original IHI turbo, which is infamous for the waste gate problem. Some consider the Borg Warner to be the turbo VW should have put on originally. They were the traditional turbo supplier to VW/Audi and didn't have issues like the OE IHIs do. The job takes about six hours, and is not the easiest thing, with a few tough to get at bolts which takes most of the time. Like the 6mm "drain plug" bolt that is one of the bolts that holds the upper heat shield in place. I made a custom tool just for that bolt. It is possible to do on jack stands, but it is easier on a lift.
There are less expensive turbo options, but I would spend more time and save up for the Borg Warner turbo than to get a cheaper ebay turbo, etc. With the amount of time it takes to do the job, you really don't want to have issues with it and have to do it again.
The turbo failure is also unfortunately common. It is almost always the result of a worn waste gate actuator linkage, which allow exhaust gasses to bypass the turbine wheel. This sets a P0299 underboost fault and the resultant reduction in performance. This is not a catastrophic failure and can wait. I would highly recommend getting the Borg Warner replacement rather than the OEM IHI. While it won't save you money, it will likely last longer than the original IHI turbo, which is infamous for the waste gate problem. Some consider the Borg Warner to be the turbo VW should have put on originally. They were the traditional turbo supplier to VW/Audi and didn't have issues like the OE IHIs do. The job takes about six hours, and is not the easiest thing, with a few tough to get at bolts which takes most of the time. Like the 6mm "drain plug" bolt that is one of the bolts that holds the upper heat shield in place. I made a custom tool just for that bolt. It is possible to do on jack stands, but it is easier on a lift.
There are less expensive turbo options, but I would spend more time and save up for the Borg Warner turbo than to get a cheaper ebay turbo, etc. With the amount of time it takes to do the job, you really don't want to have issues with it and have to do it again.