Okay, I'm back and I've cleaned up a couple of pics that may help. Unfortunately I didn't take as many shots as I thought so I'll have to just describe a couple of things.
First, bushing removal. To make it easy, the key is to rig up a mandrel to push out the bushing. Here is a pic of the fancy mandrel setup:
It is just a stack of washers that are sized to push out the bushing, but fit in the bore of the arm. I made a couple of these, the short one to start the process, and then switched to the long one to finish. Note in the pic also is an example of a pretty worn bushing - in my case it was an obvious candidate for replacement.
I bought washers in bulk at my local TSC store and they happened to be a perfect size: 0.743" or there abouts outer diameter. I'm sure you can find them, but if you can't, pm me your address and I can probably mail you a couple of them pretty easily.
With the mandrel, I pushed out the bushings with my bench vice. Sorry, no picture on that one, but it is pretty simple: mandrel on one side, oversized socket to receive the bushing on the other side and tighten the vice to remove.
One bushing was very tight and I really couldn't get it to budge with my vice, so I tried a 2nd method which worked well, and I do have a picture:
For this, use the same washers on one end, the socket on the other, and a long bolt and nut to hold everything together. Put it on the ground, tighten the nut and the bushing finally releases. This method only works to break free the bushing, but the bolt head eventually draws into the arm so you can't completely remove the bushing. Once you get the bushing started though you can complete removal by putting it back in the vice.
On to bushing installation. Pretty easy, use the bench vice, make sure the bushing is square to the arm, and make sure the hole in the bushing lines up with the grease fitting:
I used a flat washer against the bushing to make sure I didn't mar anything.
Finally, reaming. I bought a fixed chuckable reamer from Enco. 5/8" HSS, pn 331-1140 cost $13.95 plus shipping. They have a good website and ship quickly. I did have to grind it down a little to fit in my 1/2" chuck:
Basically a little cutting oil, slow rpms and careful feeding of the reamer into the arm held by the bench vice. I didn't take a picture of the operation but it would have been pretty embarassing to show the jury rigged setup. I carefully did 3 of 4 and was very happy with the results. I rushed the 4th and wound up reaming off center and had to order a replacement.
In the end though, the bushings fit the trunnion with a little play evident but overall I was pleased with the final fit. If I were to do it again, I would consider buying one or two adjustable reamers from Enco (Size B&C about $35 combined plus shipping). Start the reamer completely undersized and slowly expand until you get a perfect fit.
Hope that helps,
Randy