Mamba Motor bearing replacement?

I think you mean the bearings are 5x11x5.
Those screws on the motor can break easily but, I was able to get them out get it opened up. I heated up the screws with my soldering iron and that did the trick. They came out without too much effort. My torch I felt was a little too big for the job and my soldering iron gets up to 840*F.
After I got the screws out. I put a piece of rubber around it and put it in the vice. Put a piece of wood on the shaft and popped it with a hammer a couple of times and the end bell opened up.
Thanks for the help.