To remove the Carrier unscrew the Screw that is found to the right of the press right next to where the Case Slide rides. After you unscrew this use the handle to lift the Carrier and place a block of wood under the Carrier towards the front of the press. Release the handle and the Carrier will slide right off of the Ram. Next you push the Index Rod down through the Carrier. Now take a screwdriver or some other type of long slender item and insert it into the shell holder that is exposed all the way through the Carrier. Take a pliers and turn the Drive Bolt (hexagonal part in the middle) clockwise, this will unscrew and partially remove the Shell Plate as well. Carefully slide the Shell Plate out from under the Ejector Pin (metal wire that pushes the finished rounds off of the Carrier).
Video on Changing the Shell Plate Carrier