The interior rear view mirror is easily R & R'd. Just grab it and give a swift pull down. Replace it by shoving a new one back up there. This hold true for most Mercs from like the mid 70's up unitl like 94 or 95 when they added autoglare.
1994 E500 (MY SUNDAY DRIVER)
1993 190E SPORTLINE LE W/ M104 SWAP
2000 BMW 528I (WIFEY'S CAR)
"Excuses are crutches for the unfounded."