These 4 reversing sensors are simplicity itself to fit and everything you need to do so, including the correct-sized hole borer, is contained in the box. However, do take your time over getting the sensors in the correct position as once you have drilled the holes, there is no going back! After that, it is simply a matter of passing the wires into the boot of the vehicle and plugging them into the control box. Finding the wire that gives power to the reversing light is simple and one wire connects to this wire, the other goes to a good earth. Place the sounder wherever you want it and the job is done. It will depend on how adept and/or confident you are, but it should not take more than an hour or so to complete.