well i'd say there is a fair bit of work getting to that trim and i'd say if you can go without it just must up to it and spray away BUT if not you have to go right into the back -pull the carpet clips which run around the rear windscreen - then undo the nuts behind them-remove the 3 steel pans. push out the rain rail and you have to be careful here as it could be delicate/fragile and you might crack or stuff it - you really wouldn't know till its out of the way
after that you right up to that trim panel. I think then its about 8 or 10 bolts to undo. and you think its off. but its held on by this black gooey crap and I had to use a bit of force

to tap it off. when you do knock it out a bit its a good idea to have some help to pull it out and definitely to help place it back in when you re-paint
overall its a pita to remove. ...but so too are the door window seal rubbers
