Step 1: Day before you plan to put the new exhaust on, go buy some Liquid Wrench (like WD40, only better for loosening bolts) and totally soak both sides of the two bolts holding your stock muffler on. Let it soak for a day. While you're at the store, buy two new stainless steel automotive grade bolts to replace the ones you are about to take off the car.
Step 2: Crawl under car or put it up on ramps.
Step3: Use socket wrench with a pipe attached, or a breaker bar to take off the bolts.
Step 4: Take old muffler out of the rubber hangers and put the old one in. You might be able to reuse the gasket from the stock connection, but a new one couldn't hurt.
Have you checked azscooby.com ? I know I saw a writeup with pictures for exhaust install somewhere.