Mine were a pretty 'snug' fit too.
The best way is to order some of the shims and eclips that fit inside. Then place the diff on something with a hole in, so that the outdrive fits through, then using an old driver and a small hammer, just tap the outdrive through. The e-clip and the shim will distort, hence the new ones to replace them.
This was the ONLY way I could get mine out too. So it had to be done.
BUT, when I put everything back together, the gears just dropped onto the outdrive nicely, without any 'force-age'.
So next time they will probably just knock out easily.