To add to Sixto's good advise....
Use a 27mm socket on the end of the crankshaft to rotate the engine in order to position the torque converter drain plug(also 5mm allen head socket). Before you can actually see the torque converter drain plug, there's a cross-member like piece that must 1st be removed as it blocks access to the torque converter drain plug. It's held in place on both sides by 3 - 17mm bolts. The torque converter drain plug and the tranny pan drain plug use DIFFERENT washers. One is silver; the other a copper color. I forget which is which.
You'll use the 14mm allen head mentioned above to drain/change differential fluid. The drain plug is the lower of the two. Be sure to first loosen the fill plug(the one on top) first. You don't want to drain the gear oil until you're certain you can refill it! I perform this procedure on a fully warmed up vehicle so as to get a good drain of the fluid and as many contaminants as possible. Once drained, I reinstall the drain plug, then refill through the top hole. I take a LONG stretch of heater hose and connect a plastic tube on one end(secure with hose clamp), then route it up towards the top of the right rear tire. On that end, I connect a funnel, then pour the the gear oil in through the funnel. If you're having trouble getting the 14mm allen heads loose, back the car up a bit on ramps so as to provide more room for increased leverage. Once loose, bring it back down to level ground.
1991 300-SEL - Model 126
M103 - SOHC
James Madison - Oppressors can tyrannize only when they achieve a standing army, an enslaved press, and a disarmed populace.
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