Idler arm removal
How big is your hammer? No, I'm not joking
Sometimes, you need to get tension on the fork/ puller, then give a good solid whack on the "end" of the eye of the center link. This causes the eye to instantaneously deform and "pops" the taper loose.
Turn the wheels, etc, until you get a clear shot at the end of the center link, IE looking nearly "straight in" at the side of the wheel wheel "inline" with the center link, so you can swing the hammer. This is best done on a lift, where you can swing underneath.
Get tension on the fork/ puller, then give the end of the center link a solid blow.