[Smokedawg]

If you will have to pass emissions next year, I would make sure you keep your stock h-pipe and right before you go in to get tested, switch back. Then after you pass, switchback to the off-road h-pipe.
To switch pipes is very simple. There should be 2 bolts on each side of the flanges coming off the headers. Those are probably rusted and more than likely will break if your car is very old. Then you will have 2 bolts on each sides of the pipes connecting from the end of the h-pipe. Just unbolt all those and drop it. Its usually easier if you have a friend. Oh ya, it would be best if you could get your car up in the air, use car stands.
I also have removed my a/c. What would you like to know about that?