I finally received my two Nutech diffs, and when I opened them up to put in the silicone oil I found them both full of grease and no sign of any 0-rings to keep the oil in the diff! If I am supposed to remove the grease and then fill them up with oil, what is the best way to remove all of the grease! Also, where am I supposed to get the 0-rings to keep them from leaking? Thanks.

Richard