Ok, first things first, start from the outboard and work in.

Outboard is farthest away from the input shaft where the tranny mates with the engine. Any covers on the outboard end need to be removed so that you can make sure nothing is keeping you bound up as you try to seperate the case. I can't remember 100% if there's a fifth gear cover on a B-series tranny or not, I know there is on a D-series. If there is, you need to remove that cover, and take the fifth gear selector fork, and gears off of the main and counter shaft before the case halves will seperate.