I'd really like to avoid taking this to the shop, so here goes.
The bar-end shifter evidently has a wedge like a quill stem, that holds it in place. There's a 6mm bolt that tightens it against the inner bar. Mine's stuck.
I've removed the bar completely and I've got it in a bolted-down vice. I've disassembled the shifter to expose the inner bolt, but I can not turn that bolt, even leaning into it. I'm a little concerned about stripping the bolt head (rounding it with the hex wrench), but I'm also wondering if I'm doing something wrong. I've tried both directions just in case it's reverse threaded for some odd reason. I've also soaked the shifter it in liquid wrench also, as well as I could.
Like I said - help!