I've done mine

I didn't need to take it off, however I did remove the rubber strip that goes underneath the window which, when removed reveals the bottom inch of the B post. Once you've cut the carbon wrap to a slightly bigger shape than the B post you just simply apply it on carefully, then heat it slightly and trim it to size with a Stanley knife (ask an appropriate adult

) then refit the window rubber strip and stand back and admire

it makes it look soooo much better