[KJ] I think I claimed 30 minutes. OK, here goes. First, get a flexible funnel at a car parts store. You need about 2 feet of flexible tube, which can be multi-segment metal (preferred) or a thin rubber tube. Either way, the top end is connected to a funnel and the bottom end has about a 3/8 inch diameter nozzle.
You also need to buy replacement washers for both the fill and drain plug. The dealer charges relatively little for these. It might not leak with the old washers, but why scrimp? Now you are ready to go:
Fill plug crush washer: 94109-20000. Drain plug crush washer: 94109-14000 (same one as for engine oil drain plug)
Wait for the engine to cool off to avoid unnecessary burns. Open the fill plug first to avoid the embarrassment of an empty transaxle. To open the fill plug, I used an 18 inch breaker bar from above. I think it was a 17mm socket.
Put the funnel and tube in place and make sure you can refill the transaxle. You might need to reach in from below, which can be done if you lie down next to the car and put your right arm behind the wheel from the front. Or you can make it really easy by removing the wheel if you don’t have long arms and you don’t like injuring your hands. I like to keep the wheel on when possible because I feel safer working under the car that way.
THEN put a pan under the transaxle and remove the drain plug from below. This requires crawling under the car with a 3/8in ratchet and perhaps hammering on the handle to break the plug loose. Drain it for several hours if you have the time to spare, since dinosaur oil is viscous. Otherwise 15 minutes is probably enough.
Using your new crush washers (you DID buy them, didn’t you?), replace the drain plug and refill. You will find that the very end of the third bottle of Redline starts dripping out the fill hole, meaning that it’s full. Replace the fill plug and tighten. No need to overdo it, since it’s not about to come loose by itself. I think the manual specifies something like 25 foot-pounds, but you should re-check that. I just tightened both bolts snugly.
[BSD] Locate tranny fluid drain plug. It faces driver’s side and is at 90 degree angle from engine oil drain plug. It is round (no sides) with a 3/8" square drive hole for a ratchet to fit. It has a washer around it too which is a more shiney silver color than the tranny case and bolt.
Just above it and towards the rear of the car is the fill plug. When changing tranny fluid, ALWAYS make sure you can loosen the fill plug before removing the drain plug. You will be very sorry if the fill plug were to be stuck.
Once both are loose, remove fill plug, then remove tranny drain plug and let drain.
Replace drain plug with new washer.
Fill with 2.9q 10w-30 oil. I have a $7 hand pump for stuff like this. Fill until 2.9q are in or until it overflows and spills out. When filling, I use a little hand pump to pump the fluid up there. No fuss, no muss. I have not tried the snaking funnel method.
Replace fill plug.
[GM] Another trick is to get a quart squeeze bottle for filling the tranny. This is better than a funnel with a long filler hose snaking to the tranny from the engine compartment. Use a 3/8" torque wrench when reinstalling the plugs. And you remove the fill-plug first in case it is frozen! Use the standard 1/2" ratched head or short extension. It should fit right in. Most drain plugs have a tapered pipe thread which gets tighter as you turn it clockwise. So torque it only as tight as it needs to be. The fill plug on the other hand uses a normal socket, and you can either replace the aluminum crush washer or as I did used the old one. Still no leak so it’s up to you. Good luck.
[DO] A 3/8" ratchet fits the drain plug, and the fill plug head is 17mm.