I had to remove the back seat on my 1987 260E in order to gain access to the vaccuum pump. The seat comes out okay, but I can't put it back. The foam is just too thick so I can't push it far back enough in order to line up the the two red tabs. I wanted to put both foot on it and push but got no leverage in the cramped space.

Any tricks, tips I should be aware off? TIA