I was gone after a wreck but I decided to keep the beast and I'm back

Okay, first of all I would like to know how the turbos are set up in my '99 T6.
Second, I really want to replace them but I don't know how feasable it is.
I found this: " Kenneth Löf in Sweden has fitted a straight six S80 twin turbo DOHC motor to his immaculate 960. Turbos are Garrett T20's. What should be appreciated is the S80 engine is normally mounted east-west, and this is converted to the 960's north-south. 278kw (378hp) at 6400rpm, 480nm torque"
However, I can't find ANY more information about anything.
I'd love stats or specs about the internals and how much horsepower is safe.

One last question: is it possible to learn to fix these cars myself? Everytime something happens it turns out to be computer related. I think the engine is great, but if I can get a new computer or engine management program I would LOVE to.

I appreciate all of your help guys, and you don't have to spoon feed me. I can learn myself I just don't know where to go or how to get the information.