I have removed plastic cap nut but can not pull arm off. The reason is right arm stopped moving so I have to get the grill off that is covering Mtr.
If you have already removed the cap and nut then just take a flat head screwdriver and pop it up to remove the wiper arm. This should work if everything is disconnected from the wiper motor.
the gm service manual says to use a battery terminal puller to remove the wiper arm from the shaft. you can pick one of these up at any auto parts store.
