I am currently in the final stages of replacing tile countertops and tile backsplash on my 50 year old house. The tile ran all the way up the walls to the bottom of the counters and was installed over a 1" thick mortor bed on wire mesh. I quickly came to the conclusion that you can not remove the tile without destroying the wallboard underneath. Rip out the entire wall (I used a 2lb hammer) and simply replace the drywall with greenboard (and cement backer board if retiling). You will have to patch/blend the edges where the new wall meets the old. It is a lot of work, just like any real remodelling...