My handle was almost too stuck to remove. It was limed on pretty good.
It is supposed to slide right off. Mine was corroded pretty bad.
I was able to get it off by wiggling and jiggling for about 30 minutes. It was only 10 years old though.
I've wiggled and jiggled quite a bit. Up, down, left, right. I've even tried it on the handle!
If the lime in the set-screw channel was an indicator - there may not be a way for me to remove the handle. I'd hate to call in a plumber for this job, though. And I'd hate for it to spiral into "now we have to re-do the master shower because the shower surround and plumbing broke"