I am assuming that you are refering to the one on the windshield. On the piece that attaches to the glass, you will need to take a flat file and file it until it it level. At the auto parts store...
it should just slide right off. pull it towards the back of the car in an upward motion. and like i said it should slide right off. if not and u really need to replace or remove the mirror just pull...
On my 1993, you pop off the dome light cover. You will see 2 screws. Unscrew them. Rock it with you hand and it should fall off. You will see a 2 pin connector for the light. Unplug it. Done.