Greases (and all petroleum products) oxidize with time. That's why asphaltic concrete paving turns gray and becames brittle. To get the old grease out/off of bearing cups and cages, I stick the parts in the oven at about 200F. The grease liquifies and the vast majority flows out on its own. While the parts are still warm, I wipe off the remaining.
If you are desperate to save a cracked piece, drill a hole advanced just a bit past the crack propagation. This cuts down on the stress concentration. This technique also works on bridges and dump truck beds.
Steve Demchak Seattle, WA