IIRC, when taking off you want to gently pry from the bottom, using a somewhat wider tool to spread the pressure across the trim. You can also place something under you pry tool to avoid paint damage. Install is the opposite - hook the top edge over the lip first and align screw holes, then gently push down to snap it in. I've seen some run a length of masking tape along the bottom to avoid chipping but personally I don't think it is necessary. The aim is to first avoid any damage to the more visible top edge of the trim.
