Since their invention in the early 1950s, Maglites have always found a way to be in the right place at the right time -- whether that means in the glove box of your car when you learn that your car battery has died -- or during the 2000 inauguration of President George W. Bush, when Maglite donated 40,000 Mini Maglites to the ceremony. Reknowned for their durability, keeping your Mini Maglite in top working condition is easy to do; a little periodic battery and bulb maintenance will provide you with a bright, stable stream of light when it is needed most.
Remove the Mini Maglite tail cap from the bottom tip of the flashlight by gently turning it counter clockwise until it comes free from the switch barrel (main component of the light). Tilt the switch barrel away from you so that the batteries drop out. The battery size and quantity are specific to each Mini Maglite, so replace the batteries with the same size and quantity removed.
Locate the spare bulb compartment that is hidden in the Mini Maglite tail cap. Remove the small battery spring which is attached to the end of the tail cap, then pull the now visible spare bulb free from the tail cap. Check that the spare bulb is still good by looking at the bulb's filament inside. If the filament is unbroken, the bulb is still good. If it appears broken, then replace that bulb with a new one. It is always best to have any extra bulb, so be sure you have one as a spare (in the tail cap), plus one in the head of the flashlight that functions.
Remove the head component (the big end) of the Mini Maglite from the switch barrel by turning it counter clockwise until it comes off. The head component contains the operating light bulb as well as a plastic lens and a reflector device. Remove the face cap that secures the head to the switch body by turning it counter clockwise until it unscrews completely and pops off.
Reach inside the plastic reflector (still attached to the head component) and pull the light bulb away from the reflector. It will pull straight out with your fingers. Replace the bulb with a replacement bulb of the same style and wattage as the old bulb.
Reassemble the Mini Maglite by following the reverse order of the disassembly instructions. Add a drop of light machine oil to the threaded components during reassembly to keep everything well lubricated and easy to twist. Test the flashlight for normal operation.