thanks, guys. I walked away.... calmed down... and then went back and looked at it again. I had thought of the wrenches from my router (Bosch... metric) but at 24mm it was a bit oversized. I had another 24mm in my toolbox so I taped some shim stock into it and got the old saw blade off. 15/16 is 23.81 mm so didn't require much to adapt a 24mm wrench. Might have been fine using a 24mm on that, but I hate the thought of rounding those flats on the arbor. Or slipping off.....
and harrysin, yes I knew about the left hand thread. hehehehe.... Wouldn't THAT have been the icing on the cake if I'd been trying to TIGHTEN it ?
I have some 1/2" and 1/4" maple and didn't want to cut it with that old 36-tooth blade.