I would add one thing, with a sharp object, i.e. box cutter, edge of putty knife, etc, score the wall first, saturate with the hot water and let sit a few minutes up to 20 to allow the water to penetrate. I would then use a wide putty knife (4 inch) and work it underneath the scores.
If you do a little at a time, this won't allow the wall to dry out. I like to do a square yard at a time.
