Unable to move gear selector '81 25hp

[garryc]

The gear adjuster on my outboard is very very stiff. I think I will have to disassemble the gear adjuster but have no idea where to start. The Seloc manual I have is next to useless.
Any advice appreciated
thanks

[boats.net]

Sometimes if you look at a breakdown of the parts, that will help. Usually the screws are in from the back.