I'm sure there is a thread here somewhere with pictures on removing it. I referred to it when I took the card off my Brera.
From memory it is along these lines.
It's pretty simple, you just have to find all of the screws in the door. Behind the plastic cover in the interior door handle, remove the electric window switch as there is one in there. 3 or 4 along the bottom edge. Remove the puddle light and undo the wiring clip from the back. You may have to remove the plastic trim triangle from mirror part of the door as there may be a screw behind that, I can't remember.
Then tease off the card bit by bit, without using anything narrow to prise it with else you could mark the door card. Don't be afraid to give it a bit of a tug, so long as the pressure is even and all the screws have been removed.
Mine had a rattle which was a loose clip, the rattle was fixed when the clip was re-seated.