Patience grasshopper. I've found the easiest way is to start on the left side, slowly inserting the axle through the various brackets, spacers and the wheel hub. Also I lower the bike down over the wheel so that it's resting on the ground at roughly the correct ride height. Then it's "simply" a matter of wrestling it all into place. All the spacers, the caliper bracket and hub have to be perfectly parallel to fit together.
And don't forget the chain adjusting brackets. Last summer while I was installing my replacement belt on my aborted trip to Idaho, I finally got it all together but in the process didn't notice that the axle did not go through the adjuster bracket. I just about lost it and kicked the dammned bike off the jack.
