If it is just leaking at the ball you should be okay to clean around it ,loosen the collar remove the 4 bolts holding the ball on then slide it back to replace the gaskets. The gaskets are also shims for the ball to move properly so you can take note of the shims on there already and would not hurt to read up on the adjustment .You can check your u joint while in there as you will have to undo the bolts to slip the gaskets over.
