When I installed mine, I put the rim on top off an older rim with a piece of old carpet between them, then I stuck short pieces of 4x4 every 90 degrees under the tire, so I could walk on the tire, and kick the ring back on the rim.
Make sure you wire brush, media blast, or chip away any dirt, scale, rust off of the locking ring, and rims mating ridge, and you will not have any problems with the locking ring coming off, if it's on all the way. STILL, as a caution I use a long hose with one of those clamp on air chucks, and plug the line 50 feet away back at the compressor.
Have never had one come apart, and since I clean them, I "PROBABLY" never will, BUT I still show them some respect and keep a safe distance away when airing them up. NEVER hold the air chuck to the valve by hand!