Brad, this is common. They make a tool that is like a 2 leg gear puller for this but I usually just use a gear puller. The tool has a small end to push against the area where the screw goes but you can put a wood block on the partially removed screw. I haven't found things like WD-40 to be real helpful for this, but putting white, molybdenum disulfide grease on the end of the stem is a big help for future problems.
You can also put a wood block on the wall and gently pry around the edges of the handle to remove it. Be sure that you are gentle enough to not cause more damage, things like broken tile, for example.