Its been a while, but I had the same problem, but I can\'t remember the details exactly.
The 3 tabs hold the cover in place, I don\'t think you need to undo them. I seem to remember having it fall apart on me.....
I also seem to remember using a hammer, and then the halfshaft came right off the companion flange. Eg corrosion set in, and effectively glued them together. PB blaster, and some gentle hits made it come right off. However, someone with more recent experience should be consulted, as I would hate to have something break due to a poor memory on my part.