You need a plastic wedge tool. You need to force it in between the white painted area and the edge of the black plastic to release it. It helps a lot if you have the new one in your hand because you can refer to it to see exactly where the clips that hold it in are. It is nerve wracking, but take your time and you can do it without marking the paintwork
The painted door cover slides off the hinged part. There is a single plastic hook you need to ease away to allow it to slide. Doesn’t matter if you break the hook because it comes on the new part