Rear Axle Bearing....

if its the left rear, it real simple. Remove hub, unbolt bottom shock mount and remove the 4 nuts on the diff. The axle tube will slid right off. Just drive the old bearing and seal out. install new and bolt everything back up

it sounds like it is the left rear...should i replace both sides while it is apart or just the one??

the left is the most common one to go out. Alittle more work is involved to take the right side loose. The rear brake assem. will need to be removed, the rear brake backing plate holds the bearings for the right rear side.

dont forget about the brake seals and felt rings , a good seal is needed to keep that water out ,and keep the axle from rusting.