Just changed mine today (RWD 3.3 LSD) and was simple. I used a 6pt 15/16" socket on the drain & fill
plugs, tried a 24mm 6pt and the 15/16 was a tighter fit, and since the drain
plugs have a shallow head on them I prefer a tight fit there as wouldn't be hard to round them off. The fill plug wasn't very tight but the drain plug took a lot more effort to break free. The drain plug appears to have a thread locker on the threads so that could be why it took more effort to break it loose. I re-used the copper washers but will order new ones next time around, have seen a few DIY videos and were reused on some of them, torqued down to 32 ft lbs on both, and used loc-tite blue on the drain plug threads.
There is a youtube video of a DIY rear diff oil change and he just jacked up one side, got under the vehicle and performed the oil change,
PLEASE DON'T EVER DO THIS, do not put your life on the line w/ a hydraulic jack as your only savior. Use ramps or jack stands if you ever work under your vehicle, and if you use jack stands sliding an extra tire under your vehicle is a good idea as well.
I used Royal Purple, have used their oils in the past w/ no issues and Amazon had a good price on a 2 pack
I used a clear bottle to pour one bottle in and mark the 16oz level so I'd know how much I'd have to leave behind as the diff takes 1.5 qts. The fill hole will also let you know when full as it will start to dribble out once it's to capacity so that saves time, just drain and then fill until it dribbles
The squeeze bottles when fully squeezed out still left about 6 oz in the bottle (since there's only enough room to tilt them up just a little) so you have to squeeze out most of the second bottle until it dribbles out the hole.
I had my car on ramps in the back and didn't level the car out in front so that's why I took the extra measuring steps, but it worked out the same, I verified that I put exactly 1.5 qts in and indeed it just started to dribble out the fill port. I poured out the drain oil and it was just shy of 1.5 qts, so all good! Drain oil was dark charcoal gray and the plug magnet had a reasonable buildup of metallic sludge but no chunks or metal slivers in the drain oil so I feel good about that.
Changed it at 40,500 miles and will do it again around 75k.
