Thats sort of a few questions in there!
The first is the turbo. If you're reasonably mechanically inclined i dont think it should be too hard. You'll want to take the intercooler off, and the downpipe. Other than that I dont think you have to remove much, just loosen oil lines, up-pipe, etc.
Fuel Pump: also pretty easy. Easier on the GR than the GD, but i have a write-up in the how-to section for a GD.
Injectors: Never done those, but i think you have to take the whole Intake Manifold off. From what I hear its a bitch. Not so much because its physically hard, but because there are so many things that have to be disconnected and then reconnected, and its sort of a headache.
As for the tune... Are you a competent tuner? I would say more "it's possible to create a tune" instead of "you can create a tune." You really have to know what you're doing. As a side note, you can sign up for a premium or Platinum membership and work with some of our resident tuners to get you a sweet e-tune. It comes with the membership basically, and really pays for itself.
fyi, a new pump doesnt require a tune, its the injectors.
