removing tile around bathtub

[ssargis]

I am getting ready to have a Corian surround installed on the wall around my tub. But since there is existing tile, I wanted to take that off so they have a smooth wall to work with. Trouble is, when I started to take off the tiles, I found that they were so cemented on, that the drywall is coming off, and I’ve basically got no wall. Is there an easier/better way to do this, or will I just have to remove the wall, and then re-install new drywall for the Corian to be set to?