Ignition switch. installation plez help.

STORY : well, if you guys have any other theories as to why i've gone through 2 starters in 2 months, i'd much appreciate it. from what i can tell, this is what happened to me the other night:
the starter engauged while i was driving the car and began to burn itself out. then the starter began knocking against the flywheel causing awful grinding sounds. it also managed to drain my battery dry.
so, when i took the starter out this morning, i pulled it open and the starter stinks (burnt).
SO, the only thing i can think of is that my ignition switch (i had help from more than a few people to come to this conclusion) is fried or something causing the starter to engauge while the car is running. i'm going to be heading over to the VW dealer to pick up a new switch for 30 CDN, but i needed help as to exactly how to install it since it requires me to take the whole steering column off. how hard is this installation to do? should i even attempt it?
VW wants 105 for labor if they were to do it. i'd probably spend 150 at the dealership for them to replace it, and i really need money right now.
if you guys have any other ideas as to what else may be causing this problem, or if i should replace anything while i'm working on my car (wiring or whatever) plez chime in. thanks a bunch for your help.
PS, i won't have a replacement starter until Tuesday, so i'll be stuck here =(.