How do you change the brake light bulb on a Audi A6 Avant 2003?

Remove square red infills at either end by inserting thin sharp blade, they will pop out. Behind are torx screws number 20(i think), unscrew (long) screws. Then the hard bit...3inches from either end are two locating lugs that need pushing down to release the light unit. You have to try to prise the light away and push them down at the same time. Hey presto light out without scratching your paint!?