Torin Troy

hello. I'm 17, 18 in a few days. And I bought a 1991 W124 300D as my first car. I'm removing the engine (and transmission of course) and I've come to removing the last few things. I'm trying to disconnect the speedometer cable from the transmission, I've undone the fastening bolt for the clamp however it doesn't want to move, am I missing anything? I've tried opening the clamp gently with a flat blade screwdriver and got a little sideways movement. however no cigar. there's also a little wire on the opposite side that comes out of the tunnel wall that I cannot figure out how to undo. Any information in getting these off would be great. Thank you in advance.