They have little plastic lugs on the other side of the door card. Just heat them up preferably with a soldering iron and bend them outwards. Remove grill, insert new one and reverse process. Just put the soldering iron on the tab and bend it easily.
Very similar to the 'How to' in my car diary on how I did the 2 tone door cards. Few pics in there that may help you.
Very similar to the 'How to' in my car diary on how I did the 2 tone door cards. Few pics in there that may help you.