Ian (from amiga-hardware.com) had a real nice writeup on how to install Amix in WinUAE on the wiki. But there was a database hiccup lately, even though I managed to repair the database it ate/truncated the article
But the article on patching to 2.1c and the helper file for the patch disk are still out there!
I'd really like to get another WinUAE article up as pretty much anybody could play with it then, but I need to resolve some hosting issues first. I'd hate for more info to be lost.