Slide hammer
I recently had to take 12 old 10.00 20's apart. Made a 40lb slide hammer out of some scrap pieces of 1/4 wall tubing, let the air out, bang around the ring a few times pull it off, squirt a little soapy water between tire/flap and rim, take a piece of flat stock (I used 1" wide by 1/8" thick) work it between the flap and rim to loosen flap and get soapy water in. Use slide hammer to bang the bead loose on the other side, pull rim out. On a really bad/rusty rim, it only takes about 10 minutes from start to finish. The hammer has to be heavy to work good! Just my experience.....made life easier!