97 Grand Am GT crossover pipe

[luapsided]

My car has been a little louder lately and I was getting some other work done when the technician pointed out a manifold leak. After a little more looking he was almost certain it was coming from the cross over pipe. It sounds like GM only makes the part for this? And its pretty spendy procedure as a whole. The whole procedure would be around $400.
Couple questions:
How easy would this be to do myself? (need to take a lot apart or can you wiggle the new pipe in there without dismantling anything)
Would it be possible to find the leak and use that exhaust hole repair tape?
He also mentioned something about a flex part that will usually go first on these. There is a heat shield on there so I can't notice anything and before I go taking stuff a apart I wanted to get a heads up. ANY information would be awesome and I hope to do it as cheap as possible. I would like to sell the car asap, and not put much more money into it and also make it sound a little quieter Thanks for your time!