[Myetball]

I had two rear wheel bearing that were installed with the shipping grease. Both self destructed. It won't happen instantly but you'll only get a couple years out of the bearings if you don't regrease. The shipping grease really isn't meant to be left in.

I used brake cleaner to degrease my new bearings (no residue). Use the little plastic tube, it really helps. After they were all cleaned I used compressed air to make sure they were dry.

By "take apart" are you talking about taking the rollers out of the plastic retainer? I wouldn't do it. One screw-up and you may need a new bearing. Of course if you're talking about the plastic sleeve pressed into the middle of the bearing, that's there just to hold it all together for shipping. Take that out and throw it away.