Getting rear dash cam cable down to rear wiper

I want to place my rear camera for my dash cam just above the rear wiper in my vrs estate ( reason being if I put it anywhere else the dog knocks it off or trys to chew it. I have got the cable fed through the rubber bellows into the tailgate but how would you feed it down the inside of the tailgate and up behind the trim.

I can't find any guides on removing the tailgate lower or upper trims and don't want break the trim trying to get it off have already knocked one of the trim clips off and have plenty of battle scars up my arms trying to reach in without removing the whole panel. The mk3 was easy but can't get head around the mk4 one?