Grab the part under the handle with your hands and unscrew it completely. Then lift it off.

If it won't budge, you need a small strap wrench for extra leverage that won't scratch the surface..

Hopefully the stem was installed properly so that you don't end up turning the whole assembly. If that were to happen, you would need to first tighten the nut underneath since you won't have access to the top nut (under the handle.) That would be a bit of a pain.

This post was edited by homebound on Sat, Aug 10, 13 at 22:03