There is no particular protocol for removing the trim attached to the driprails. In most cases it is a good idea to bend an old flathead screwdriver slightly. Many of these moldings are held in place with black glue (similar to window ribbon) and possibly one screw toward the bottom. When the outside temperature is on the warmer side, these moldings release much easier. During the winter months, you may need to employ a heat gun to assist in softening the glue.