I'll share my method. It's probably wrong (of course), so someone who knows a better way please post it here.
I've done about a dozen so far...remove valve core, then remove outer locknuts. You'll need a duckbill or forklift to break the bead, then remove the outer wheel half. Flip the tire/wheel over & break the other bead, then flip tire/wheel over again & prop tire sidewalls on wood blocks so wheel can fall free. I use a sledge hammer to drop onto the inner wheel face, and work my way around the wheel in thirds or fourths to "walk" the inner wheel off of the runflat....you don't need to strike with the sledge hammer, just use its weight to drop onto the wheel and encourage it to work itself off of the runflat. I can usually completely demount a 395 tire with runflat in 20-25 minutes this way.
When you break the first bead on the outer wheel half, please make sure you've removed all the outer wheel locknuts first...you'll find that when the bead finally breaks free, the outer wheel half will almost pop right off of the tire/wheel. Steel MRAP wheels use 1-1/8" nuts, FMTV wheels use 15/16" nuts. I don't know what size of locknuts the aluminum MRAP wheels use, sorry.
The runflat will have a black, tar-like substance all over it & all over the inside of the tire. This is a lubricant in case the tire goes flat, it keeps the runflat from overheating. You can't totally get it all off, so don't bother.
To remount the tire on another wheel, just reverse my directions and use LOTS of dish soap or tire butter. You can work the runflat back over a new wheel half in the same way. It is very easy to seat the new bead; simply stand the tire back up on its tread and inflate (preferably using a locking air chuck and standing a safe distance away, you never know). The bead is practically seated once you torque down the outer wheel locknuts.