7 1/4” Rearend Disc Brake Swap

All I need to do is switch to BBP from SBP on my 7 1/4, don't have to have rear discs, would love to, but no need. What is the procedure for this? Ordering the Dr Diff front disc kit already. Have a guy that will redrill my axles, do you folks just redrill the drums, or is there a drum that will fit I can get from the parts store that is a bit of an upgrade maybe?