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.
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.
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.
