http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0403.htm

http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0404.htm

Removing the old bearing "race" might need a tool.
Maybe other members will confirm and post advice on this?
(I have only done this on three trucks - all 3100 48-54)