Damn it all
I guess this is how Park Tools locks you into using only THEIR tools. They're using an ever-so-slightly non-standard bolt size on the lockring removal tool, so neither of my wrenches fit. I have a (non-Park Tools) wrench that is specifically aimed to fit a standard lockring removal nut, and the hex hole is just barely too small. I tried my adjustable wrench, and it's the same flippin' deal. The maximum adjustment size of the wrench is less than half a millimeter too small to fit the nut. Ridiculous!
Yeah, make fun of me all you want, but I already took an hour out of my day to bike down the mountain to my LBS and I just don't have time to do it again.
I have a spare chain lying around... I suppose I could just grip the casette with the chain and use hex hole on the backside of the Park Tools chain whip on the Park Tools lockring removal nut? (surprise! it fits perfectly! maybe I should have bought two!!!!) Would this work? Or would it just mess my hand up even more than it is after getting my thumb caught in my crankset yesterday while I was pedaling? Don't ask...