Bobchad
The tool is called a rear wheel bearing greaser.(not too elaborate) I bought mine from Vette World for $12. You can find it in all of the vette catalogs for $12-$17. If you use this method to re-lubricate the rear wheel bearings it should be no more than a couple of hours work. You need to unbolt the wheel end of the halfshafts, mark the strut rod chamber bolts(so you can get them back in the same place), loosen and turn the chamber bolt to move the wheel away from the halfshaft until you can move it over out of the way. Remove the cotter pin from the spindle nut, then loosen and remove the spindle nut, flange, and washer. This exposes the inner wheel bearing. Install the greaser tool, replace the nut to hold the tool in place and grease away. Use high temp wheel bearing grease only! Reverse the procedure when complete, replace the cotter pin, don't re-use the old one.