Attention: TDR Forum Junkies 
First remove the fill plug, if the fill plug will not come out, then don't take the cover off until you remove.
I usually take out all bolts but the top 2, loosen them so the cover can open a bit to drain fluid.
If the cover is "stuck" you can use a 2lb RUBBER mallet to sometimes bump it loose, other wise a screwdriver with some light tap from a hammer to get under the cover a bit will allow you to pop it off. Careful not to damage the gasket by going in too far...
Let the fluid drain in the drain pan, then remove the top 2 bolts, I wipe down the cover on the inside. When I did my change at 60K I wirewheeled, sanded then painted with rust reformer, then black chassis paint. I let it dry over night. I take a mid size trash bag and cover the open diff to keep stray stuff from getting in it over night.
Then reinstall cover, tighten bolts to spec. [I have to look it up, but not too tight, otherwise you can break them off in the diff which is a whole nother story to remove]
Refill with 75W-90 synthetic, your flavor of choice. I believe up to 1/4 inch below the fill hole edge, a coat hanger bent at a 90 makes a good dipstick.
Have fun
Luke
