2004 E320 Cannot figure out--even with the manual--how to fold down rear seat to enlarge trunk. There are no handles to pull, rear seats do not fold downward toward the back of the front seat. What gives?

i just ran into the same issue right before i was about to move some long items. i even rtied to remove the seat which i thought would work fine, but instead there is a wall that will not move between the trunk and back seat. apparently the folding rear seat was an option. some how it did not come w my 04 e500 which i just can't believe.

Ok there are 2 little access points on the seat cushion (bench style), I can flip a lever each side and lift it a few cm. Now what?