It really is that straightforward, at least on my 450sl. Just yank down on the mirror (a good solid yank is needed, don't be shy), and you'll see the screws to remove the trim strips that will give you access to the real screws to tighten the visors. Takes like 5 minutes per visor.

__________________
Tjohn

82 300 SD
77 450 SL (gone)