Hi, I'm Chief Joe Bruni. The installation of a smoke alarm or a smoke detector is relatively a simple procedure. There are basically mounting hardware pieces that come with every smoke alarm or smoke detector. They entail a couple of mounting screws and sometimes mollies, or plastic hardware that are inserted into holes that were drilled into the ceiling or surface area where the smoke alarm is to be mounted. The first step to mounting a smoke alarm is to take the mounting surface backing plate, or smoke alarm itself, where the mounting hardware will pass through, and use it as a template. Place it up against the wall surface or ceiling surface where the smoke alarm is to be installed, and mark it with some type of pen or pencil. The next step would be to remove the template or backing plate and make two small holes, either with some type of a drill or some type of a punch and insert the two mollies or plastic hardware pieces that come with the smoke alarm. Replace the the mounting hardware bracket back over those mollies or holes, and install the two screws that come with your smoke alarm hardware. If the mounting surface for the smoke alarm is other than drywall, you would want to use the appropriate fasteners for the type of surface that you're mounting the smoke alarm in. Use the proper hardware that comes with the smoke alarm, or you will have to purchase the proper mounting hardware to mount those screws or that mounting hardware into a wood surface or plaster surface, other than sheet rock or drywall. Once the mounting hardware has been put in place for the smoke alarm installation, you're almost there. All that's left to do is place the battery into the smoke alarm into the proper carriage or holding area for nine volt battery, assuring that polarity is correct on the battery and the contacts within the smoke alarm. Test the smoke alarm by pressing the test button on the face of the alarm to make sure it sounds a chirping or beeping sound, ensuring that the smoke alarm is working properly. Then, simply install the smoke alarm on the mounting hardware backing plate that you've installed on the mounting surface. I'm Chief Joe Bruni. Stay safe.