I figured it shouldn't be that hard either. The difficulty I'm having is primarily with the chassis end. The threaded end goes in fine, but due to its entry angle it prevents me from putting the rear bush in and getting the bolt on even to the first thread. It's almost like it needs to go straight in, bolted up, then have the other end pulled down to meet the axle, but the axle location won't allow that. I'll take another swing at it tomorrow.
So jack up the radius arm from below so that it is straight, suck it in with no rear bush, just washer and nut, then remove the washer/nut, install bush, reinstall washer and nut.