Reattaching heads and limbs

Hi guys, hope this is the right place. I'm in the process of making a bearded UFC lesnar and fatter 2019 Jericho. Ive removed the arms legs and heads for sculpting and painting. I just wondered whats the best way to get them back onto the torson again, surely hot popping or hair drying them wont work because of the paint?
Any help would be apprdciated