Thank you, that is helpful, yes I've had the stepper motor out a few months ago, coolant/chips had accumulated and rusted out the stepper motor internal bearing. new motor, $125 or so, not bad.
So, to clarify, once I get the stepper motor removed (I'll leave the coupler on the stepper motor shaft, easier that way), use a socket on the 'castle nut'?, I assume it is conventionally threaded? Problem we had, turning the castle nut, the feedscrew wants to turn.
bearing block bolts have some rust on them, so will hit with wd-40 and let sit for awhile.
DO you happen to have a part number for the nsk bearing?
This is a lifesaver, thank you I really appreciate it.