No.... you would not whack them sideways. That would just break them off. You are trying to pull them out. Tap the vicegrips in an upward motion. A slide hammer would be better. OR.... just grease them and leave them alone. The ball doesn't have to be present for them to work. It does keep water and dirt out of the fitting though.... but as small of a hole and your dealing with, I wouldn't worry too much.
You can get threaded grease fitting at any parts, or farm store. Nothing special, nothing fancy, and definitely not application specific. Threading the hole without getting metal particles in it isn't too hard. Just coat the tap with grease before using it. Pull it out often and clean. When tapping is done, (and you don't have to tap them deep or sometimes at all if you get self threading grease zerks) then just use a small screwdriver in the hole to get the grease/metal out. Don't make this too hard.... it's really easy.
