You should be able to pull the interior door handle (chrome) back to reveal a black plastic cover the hides the small phillips screw. Once you remove that you should be able to expose the larger phillips screw that holds the armrest in place.
1994 E500 (MY SUNDAY DRIVER)
1993 190E SPORTLINE LE W/ M104 SWAP
2000 BMW 528I (WIFEY'S CAR)
"Excuses are crutches for the unfounded."