Well Bob, I'm glad you asked.
I don't know how much the transmission holds but if you pump it out through the pipe that connects to the top of your transmission cooler you can get about 3.5L out.
As for the diff, I think it was 1.3 or 1.4L. It's got a funny looking nut that is a circle with a square hole in it for both the drain and fill hole. What you do is stick the drive of your socket set (don't use the ratchet, use the bar with the square drive) in there. It was bloody tight and the zorst got in the way a bit which was kind of ok because it was partly off it's rubber holder thingie and this made me notice it.