how to change tran/axel bearing in tranfer case at cv shaft

I'm pretty sure you mean differential. Any of the internal transmission or differential bearings on the inside where the axle shafts go into must be serviced by transmission and differential disassembly. This is not a "do it yourself" job.

Stick your finger inside and roll the bearing - I think you’ll find it turns rather nicely! You can’t observe the bearing rotating - the whole assembly does not turn - only the rollers that contact the axle shaft is what counts.. Additionally - IF the bearing has failed - there would be very obvious damage to the original inner axle shaft as well.. Good luck