The Honeywell glass break sensor can be opened by a screwdriver. All you will need is a Phillips head screwdriver to unscrew the three screws on each side of the bell housing, and then use your hands or an object with a flat surface like another piece of metal in order to pry open the casing enough for access. This process takes about 10 minutes as it involves removing approximately 5 screws from each side before finally gaining full access into what should now look like two halves – one has openings where wires are coming out, while the other half has just holes with nothing but empty space inside that looks like broken glass shards.