hey nick - i just solved that exact predicament this past w/e. i have the 8mm UE cvds, dace 23mm adapters, and the nut on the cvd's is 10mm. i went to lowe's and bought a $3 deep well 10mm socket, secured it in a drill, and took it to a bench grinder for about 2 minutes. i reversed the drill rotation from the grinder rotation. worked perfectly - just take small amounts off and keep checking the fit. now i have a custom socket just for the purpose of taking those little nuts on and off.
i also picked up a 7/8 socket (lowe's was out of regular 22mm sockets, which is what is needed for the 23mm nuts. the 7/8 works just as well. there is a little bit of slop, but not enough to do any damage)