I just noticed this message. I presume that you found the Disco3 link below as you have the info re the JAE connector.
DISCO3.CO.UK Photo Gallery - Switch Replacement Rear Upper Hatch Release
No, you do not have to pull the license plate off or anything really, you just pry the old switch out, that is if you are doing the mod. Wait until you have the new one so you can see where the spring plastic clips are.
Removal is supposed to be easy but it is not. I did not wreck mine but LR has changed the design a bit so removal of the new switch would be even harder. The newer design glues the soft rubber bit to the hard plastic behind so as to stop water getting in between that causes the problem, (corrosion), in the first place.
continued new message - thousand letter limit.