I didn't separate mine when I cleaned it. If you REALLY want to clean it out good, first clean all the old grease up with a rag, and then either put it in a parts cleaner (which i'm guessing you don't have) or get a few cans of brake cleaner, and spray it down really good. Let it dry for a while, and then repack it sort of like you would a wheel bearing.

88 4R, 350 V8, R150 5 speed Sold <...uot; />
97 4R, stock, daily driver
98 Sienna, kid and dog hauler, wife's ride