Wheel/Axel bearings...

Any auto parts store should be able to get you a rebuild kit for your 8.8 rear end.
http://store.summitracing.com/partd...925134+4294821803+4294848677+115&autoview=sku
or maybe these
http://store.summitracing.com/partd...1&N=700+150+4294925134+4294821803+4294848677+

To change the axle bearings, at the outer ends of the housing is straighforward.

You need the bearings, available at any parts store, as well as the seals, some rtv for the cover, and some gear oil.

Replacement bearings are $10-15 each If the axle shafts are worn where the bearings ride, there is also a special repair bearing, with a sleeve that fits over the axle. They are $45 or so.