Ive only ever split Kawasaki cases so this may not apply to all, but i install install the shiftdrum, forks, gears, and crank, all on one case, then slide the other case on. the first case hold everything inline, so its a fairly easy process, only thing is you got to work quick when using a frozen crank and cases fresh out of the oven
also a case splitter is a must, never hit the crank with anything, just putting it out there