Select a location to install your fire alarm. You should chose a spot in the middle of one of your ceilings, away from any sources of draft.
Set up your stepladder below the location you've chosen to install your alarm.
Remove the cover from your alarm and hold the back panel in position on your ceiling.
Make marks on your ceiling through the screw holes on the back panel of the alarm.
Drill holes into the ceiling where you made marks with the pencil.
Insert rawl plugs into the holes you drilled and screw the back panel of the fire alarm into place. You need to make sure that you're using the right type of rawl plugs for the material your ceiling is made out of.
Connect the free battery that came with your alarm and secure the front panel into pace.
Hold the test button to make sure the alarm is working correctly. The alarm will sound if it is. If the alarm doesn't work, remove the front panel and check that the battery is connected properly.