If you have been banging on it that hard, I would go get a replcement. To seperate the shaft from the joint, remove the snap ring first. Then place the joint in solvent and clean very well. SPOTLESS. old grease and new grease will some times not mix together if they are different. Could lead to seizure upon high stress condition, such as high speed turns. I do not recall having to dismantle to joint itself. The bearing case, center yoke, and housing should stay intact. If you remove the bearings, they must go back in the original spot. Look at it this way. You have a pair of shoes that have a perfect fit to you. Now, take them off and put them on the wrong feet