Pull the pin located at the top of the fire extinguisher. This will release the locking mechanism allowing you to discharge the fire extinguisher.
Aim the nozzle at the base of the fire, not at the flames. This is extremely important in order to extinguish the fire as the fuel for the fire must be put out.
Squeeze the lever slowly. By squeezing the level this will release the extinguishing agent in the fire extinguisher. Do not release the depressed lever till the fire is out. If you release the level the extinguishing agent will stop flowing.
Sweep from side to side. Move the fire extinguisher back and forth until the fire is completely out. Operate the fire extinguisher from a safe distance, several feet away. Only move towards the fire once the fire starts to diminish.
Read the instructions on your fire extinguisher to ensure that you are familiar with the operation of it as different fire extinguishers may have differnt distances to operate from what was mentioned above.
Remember to aim at the base of the fire and not on the flames themselves.
Once the fire is out, remain at the scene and monitor the area for a few minutes to ensure that the fire does not re-ignite.