Yes, there is another way- do what the "through hole" BMW owners did when they had to change the final drive lube- disconnect the drive and turn it upside down. The lube will run right out of the filler hole.
Another possibility might be to use a mandrel and bend a piece of tubing to an inner diameter (of the bend radius, not the tubing radius) very slightly larger than the centerline diameter of the ring gear; insert the tip of the tube into the filler hole and drive it about the inside of the drive housing so the the tip rests on the bottom and then suck all the lube out (easy boys!).
Yet another method might be to remove the drain plug but instead of replacing it and thereby running the risk that it might strip the threads, use an aftermarket rubber plug made for stripped oil pan drain holes. They work OK but they are cheap enough so you can use a new one each time.
A good method also might be to start off as above but instead of re-using the drain plug, just pack the drain hole with cotton loose weave with a hammer and punch. This is the way old shipwrights drove cotton in-between the planks of ships so they did not leak..... so fast.
Finally, you could get a large diameter hose clamp and a piece of flat neoprene about 3/4" square. Throw away the drain bolt, place the neoprene on the flat on the bottom of the drive that contains the bolt hole for the drain, wrap the whole thing with the hose clamp and tighten. It will work, be reusable infinitely, and have that cool, hayseed look about it like the old Massey- Ferguson out behind the barn.
Cork, carefully tapped into place in the drain hole, should also work extremely well and then you could smell said cork to determine the drive lube's vintage and overall quality.
Finally, are you sure you even need lube in the final drive?
A large midwestern company's Human Resources director was filling out a gov't questionaire. One of the questions was "How many employees does your company have, broken down by sex. He responded: Alcohol is more of a problem for us. Maybe you don't really need to strip the drain bolt in the first place? But always remember, paranoia is just good thinkin' when everyone is looking at you....
Brian
I've become a bit paranoid about changing the final drive fluid. With well documented issues with the drain plug hole stripping out I wonder if there isn't another way. Would it be possible to draw out the fluid through the fill hole using a hand-held pump like a mighty-vac? Am I crazy to even be concerned about it? Also is it true that wearing tin-foil on your head keeps the FBI from reading your thoughts and planting subliminal messages? 
