If the front one is the same as mine (and it appears so from your picture) then it doesn't 'come off' so to speak. It's moulded into the centre grille. Having said that, the centre grille does come out as a single part, so you could take it out and mask the rest of it. You should find a single screw fixing coming through the outer frame into the grille (right at the top, about a third in from the left). Remove that, and the bottom just unclips.
The rear is part of the handle I believe? I have seen at least one how-to for removing that, so have a look for 'removing boot handle' or something like that.