I find that a standard sledge with a few pieces of angle iron makes for an easy time breaking these wheels down (there are more than one post showing the process with photos...). Nice thing is that you can use three at once to help wedge and hold down the bead on older tires and you can leave one or two in on one side of the gap to hold the tire down when you put your lockring tool on the other side to pop the ring off... It's a method that the late Scrounger showed me...
Valve stem goes on opposite side of the tire from the gap in the lockring (or, in order of assembly, the gap goes on the opposite side from the valve stem...).
When you put the wheels back on the truck, orient the valves 180 degrees apart on the rear duals (you can't quite get them exactly 180 apart, but you can come close...).
A thread with photos that I took showing the process and tools that I use is located at
9.00x20 Tire Question | Page 2 | SteelSoldiers
Good luck, be safe, and if it looks wrong, it likely is...