Mark the area wherever you want this plate to go with a jigsaw and a wood blade, then away any remaining material with pliers or a portable vacuum cleaner to complete the project. If there is an unnecessary amount of gap here between framing and the desired position for the striking plate, wood spacers and screws can be used to generate some additional space. Then, using clamps or a portable vacuum cleaner, remove any surplus material from the area where you want the strike plate to be installed.