I was in the exact same spot last May, with the same questions you have.
I have a Carefree of Colorado awning, and decided to bite the bullet, order the fabric, and do it myself. It turned out fine.
As others have said, you will need 2 people. Took my wife and I about 2 hours (were both around 50). Had some minor hiccups but got through them (like, 1 screw being really hard to get out on the top rail, fabric "melted" onto the roller tube so we had to get scissors and cut off, etc. Nothing major though). The cost of replacement fabric was around $430. Carefree was great to work with- there were a bunch of specifications that I needed to choose from their website, which...I had no clue which values I needed to pick. I sent Carefree my current serial number, and they told me the exact options I needed to pick from their website.
The video already linked above was one I watched, but- since each awning is slightly different, had found this Carefree of Colorado awning replacement vid on the Tough Top website- probably watched this thing 10-20 times.
Carefree Of ColoradoMy big concern was the torsion spring. Unwinding turned out fine. You do need to count the number of times it unwinds so that you can wind it back up the same #. The number of winds is slightly different for everyone. I think mine was wound 11 times. As I was winding it back, it was getting REALLY tough to wind around 8-9 cranks, so I think I stopped at 9 and said screw it. It's been fine with 9 winds.
Old awning:
New awning:
2011 KZ Coyote 232SS
2011 Expedition 3.73