I don't think the PO ever changed the differential fluid in my car. I used a 14mm 1/2" hex driver from Snap-On and a 18" breaker bar to free the plugs. I used a cheap pump for a stubby quart bottle to fill the diff with M1 75W90. I changed it after 10,000 miles and solid debris came out, changed again after 10,000 miles and some more solid debris came out - the fluid dark both times.

I recommend to anyone that hasn't changed the diff. fluid in a while to change out the synethic fluid early and several times before running it for a long time.

Brian