It should be pretty easy to do. The lever that is attached to the shaft has a large notch on it so you won't be able to put it on the wrong way. Beneath the rubber boot is a typical seal. With some patience and a seal puller you should be able to yank out the old seal without pulling the shaft. FWIW I had my AGS upside down and it appeared to me that the vent was somewhere around the selector shaft but on the opposite side of the seal. My AWY had a normal vent up on top. I'm surprised to hear that you are losing a lot of oil that far up on the gearbox.Steve
The circlips for the drive flanges were the fun part though. Why they couldn't just put eyelets in those clips is beyond me. Heh.
Chrissev: I just went and ripped the seal out of my AWY for kicks. It took me under 60 seconds to dig the seal out with a screwdriver. The rod is hardened machined steel so it didn't even scratch. Even so, I suggest using a seal remover if you have room in the car.
Um...you DO need to compress the flange to remove the circlips unless you don't like your hands and/or face. There is a TON of force in those springs. I used the flange compression tool, removed the circlip, then remove the tool. I didn't realize since this is my first flange, that the flange was actually stuck in the splines. I used a screwdriver to try to pry it up, and BOOM it shot up and literally hit the ceiling of my garage. Luckily I wasn't leaning over it.The second flange wasn't stuck and came up gradually with the compression tool.If the flange doesn't push up against the tool for about an inch or more past the circlip mouting point then it's stuck and be VERY careful with it.