[der Geist]

I ended up trashing the stock bolts and using some quality stainless off-the-shelf hardware to replace them.

You can count on replacing these for sure. Mine were rusted so badly they all just broke off. It is super easy to do.

do I need jack stands or a lift

Anytime you get under a car you should have it on jackstands. NEVER get under a car without jackstands being firmly in place. Get a small floor jack and a good set of jackstands.

do I need a second set of hands to help, etc.

The stock muffler is pretty heft at 40+ lbs. It surprised me when I dropped it how heavy it was compared to the replacement. You should be fine on your own but it never hurts to have a spare set of hands.

If you are the least bit handy with a wrench you can do this. I would never pay anyone to do it.