That's brill, sweet.. So it's battery and tray out, undo the 8mm bolts and pop off..
Yep,first see if anything is obstucting the linkage mechanism first.
Its a large metal bar with a ball stud at one end,and the gearbox cable attached to the other end.
The mechanism itself is held in the gearbox casing with 4 bolts on the top,and one 14mm bolt below the black hydraulic hose,
if u slip your hand down the right handside of the mechanism.
The second picture is what the whole mechanism looks like
The first is with the mechanism removed.