Sure enough, it can be done without a machine shop! I rented a $150 set of cam bearing pullers (came with a slidehammer and various puller heads that were size adjustable) from autozone. Use this set to pull the inner bearing (smaller of the two) out of its journal. Do this one first otherwise you will damage the outer bearing while trying to get the inner bearing out. Once thats out, use plenty of brake/carb cleaner to make sure the journal is free of debris. Using just your hands, gently align the new inner bearing (make sure the oil feed hole on the bearing is aligned with the hole in the block) as best you can and press it on enough so that its straight but doesn't fall off the opening. To push it in I again used the slidehammer with the biggest puller attachment screwed completely open. You can knudge the slidehammer handle against the front bearing hole to get a good straight line and have a friend hit the end with a rubber hammer. Make sure he doesn't hit it until you tell him "go" each time, otherwise you can get a little carried away and score the new bearing when the slidehammer slips between hits. Keep at it, it'll eventually get in there -- patience is key.
For the bigger outer bearing I simply used a socket of about the same size with an extension and a rubber mallet. Tap it all the way out and again thoroughly clean the journal with brake/carb cleaner. Align the new bearing like with the first one (making sure to align the oil feed hole) and gently start it with the rubber mallet. Finish it with the socket. Never force it, if you wedge it bad enough you'll ruin the bearing.
Once both bearings are in, lube them with lubriplate or your favorite assembly lube and gently insert the driveshaft. If its really tight you're gonna have to get creative as demonstrated in exhibit one:
After about 5-10 minutes with this home-made scotch-brite-pad-on-a-stick(tm), clean off any residue with carb/brake cleaner, relube and try your driveshaft again. There should be very little resistance in turning the shaft by hand from the front of the block, and definitely no side-to-side play. A little resistance is OK.
Most important thing is to be patient and not get frustrated. Take a break if you have to, don't force anything. If you don't think you can handle that, definitely have a shop do it for you. I didn't have the option since I'm on a tight schedule and this had to be done!
Edit: Make sure you measure the thrust collar clearances as well, they should be within spec otherwise you will either need a new oil pump driveshaft or have a shop refit it with a new collar. Mine was dead on at minimum clearance specs after 165k miles, pretty impressive!
Edit 2: Edited above to include aligning the oil feed holes on the new bearings. Thanks and good catch IJ!
