I'm not sure that wheel is the RH-5, it looks like a 2-piece Lock Ring.
If I'm right the silver ring at the tire bead will be missing it's locking lip at two places 180* apart. To take it apart you deflate the tire, separate the ring from the tire, push the ring and tire bead down, find the two sections that don't have the lock lip. Think of these two spots as 3 and 9 o'clock, now put a pry bar/tire iron at 12 o'clock (there may be a little slot for the pry bar). then step down at 6 o'clock and pull the ring up and over the lip of the wheel. Because there is no lip on the sides (3 & 9 o'clock) the ring will slide past that area and come off.
It may require a tire hammer to get the tire bead to release from the lock ring and the back side...tire lube will help.
Hope you had your Wheaties for breakfast!
A big truck tire shop should also be able to break them down for you.
Mike B
