I have a 1981 60HP 2 Cyl Mariner 675 (made by Yamaha?). I want to remove the lower gear case but my manual does not say how to release the top of the gear shift rod / reverse locking cam. I assume I release it at the top end just under the power head but there is not much room to manoeuvre or even see. Does anyone have a procedure for this? All the lower bolts are off. Thanks