What bearings do you mean? Just the axle bearing on the outside? That's a simple job.
D-35 Axle Shaft Removal
Follow that guide to remove your shafts. Once that's out, take a crow bar, screwdriver, etc. and pull out the oil seal. Might need some PB Blaster to break the rust up. Don't scratch up the axle tube itself or you'll have leaks. Then, take a slide hammer - stick it past the bearing and slam it out with force. It may take a while, but you'll get it. Then the installation is just the reverse. Use the slide hammer to EVENLY put the bearing back inside, tap on the oil seal with a block of wood. Axle shaft back in and drum on and you're good to go.
There's a good oil seal video that I used the first time I did it.