The cover slides off after you release to tab, I'd pull the mirror and look behind the cover, you've got to tug pretty hard even after releasing the tab. Yous should have manually folding mirrors that are spring loaded, you can fold them and look behind the cover for the tab, just be careful not to gouge the paint.
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.