I've just done this after a turbo check and clean as part of head replacement thanks to metal swirl flap detachment. Ned at Autolusso said a new oil feed pipe isn't needed. It's a rigid steel pipe so does't deteriorate and can be cleaned. He did say though to remove the gauze filter from the banjo bolt. The mesh is very fine and blocks easily, killing the turbo instead of protecting it. It's reluctant to come out, I had to drill out the plastic body. Aside from that, new copper washers are all you need.
Trickiest part is the ferociously sprung V-band clamp that secures the front cat to the turbo. Needs a deep 16mm socket to undo, then springing it open - I used tubes over the ends, but a threaded stud with nuts on the inside is more sophisticated. N b putting it back is impossible unless opened up enough, so the tangs are parallel.
