We installed this bathroom faucet a couple years ago and have recently had a slow drip on the cold side. We wanted to remove the faucet handle to replace the washer but cannot get it to come off! We have removed the set screw (see picture) but the handle won't lift off -- can't figure out what's holding it in place or get to any of the parts. We can't remember the make/model or see any identifying marks or name in order to look up any instructions about it. Does anyone have suggestions or recognize the model so that we can try to get this fixed? We even had one plumber look at it who couldn't figure out how to remove the handle, either. Thanks for any help.