I just removed my K04 and sold it on Saturday for my GTI with a blown engine. It was the first time I've ever done anything like this. The write-up above is pretty good, but I went a bit of a different route. I found it to be easier to remove the K04 from the bottom since I didn't have an extra set of hands. In order to do that, you need to remove the axle, which is really easy, you just need the proper tools and triple square bits. Break loose the axle bolts while the car is on the ground too to keep the axle from spinning, make sure you have a big breaker bar. If the car is already jacked up, just shove a screw driver in the rotor to keep the wheel from spinning.
The coolant lines are a p.i.t.a. They never stop leaking the entire time and trying to fit your hands in to remove them stinks. You need large triple square bits for those. Just take you're time and remove them properly.
The manifold bolts are 12mm. The top ones are easy once you remove the heat shield, the bottom one's are much tougher and there's no way you're getting a ratchet on several of them. My 12mm crescent wrench was like 5" long and the space it had to go in was very tiny. It helped to duct tape a longer wrench onto the 12mm wrench to make it about a foot long, that way you could get leverage on those last 2 bottom manifold bolts on the right side of the engine. Having the extra working space with the axle removed was also awesome, I highly recommend it.
All together it took me about 6 hours to get the K04 off, which included two trips to Advance Auto to buy the 24mm triple square axle hub socket and multiple sized triple square bits. I think I could do it in half the time now that I know what I'm doing.
Good luck.
Edit: I sold the used K04 for $425 on Saturday. (link to my Golfmk6 thread parting out my mods:
LINK) I also included the 3Bar MAP sensor for free. If it's an APR Borg Warner K04-064, you will need that MAP sensor on the turbo inlet pipe.
