How to Unload a pistol

1.Always keep the gun pointed in a safe direction.
2.Always keep your finger off the trigger until ready to shoot.
3.Always keep the gun unloaded until ready to use.

Revolvers

A revolver is a pistol with a revolving cylinder that holds cartridges in individual chambers. Each time the hammer moves to the rear, the cylinder turns and brings a chamber in line with the barrel and the firing pin. When the hammer falls, it causes the firing pin to strike and fire the cartridge. In single-action revolvers, the trigger performs only one action - releasing the hammer. The trigger does not cock the hammer. The hammer must be cocked with the thumb, and will stay in a cocked position until it is released by pulling the trigger. In a double-action revolver, the trigger performs two tasks. When it is pulled, it will cock and release the hammer. Most double-action revolvers can also be fired in a single-action mode by manually cocking the hammer with the thumb.

To Unload Single Actions:

Hold pistol in left hand by cupping hand so that the trigger guard is in the palm of the hand with the left thumb on the left side of the cylinder, and the index and middle fingers on the right side of the cylinder. With your right thumb, open the loading gate. (*If the cylinder now turns freely, SKIP the next step.)

Use the right thumb to pull the hammer back two clicks.
The cylinder should now turn freely.
Grasping grip with right hand, use left thumb and fingers to align a loaded chamber with the loading port by turning cylinder.
Elevate muzzle in a safe direction; using left hand, push cartridge out of chamber with ejector rod.
Continue process until all chambers are empty.

SLOWLY rotate cylinder with left thumb and fingers while inspecting each chamber to be sure that all cartridges have been removed.

Close loading gate.
Place right thumb on hammer spur.
While controlling hammer with right thumb, pull trigger with right index finger to release hammer, using right thumb to gently lower hammer completely.

To Unload Double Actions:

Use right hand to place pistol in palm of left hand. Operate cylinder release latch with right thumb; push cylinder out with the two middle fingers of left hand. Place left thumb on ejector rod and elevate muzzle in safe direction. Use left thumb to push ejector rod completely to rear, removing cartridges from chambers. Inspect all chambers to be sure that they are empty.

Semi-Automatics

A semi-automatic is a pistol that has only one chamber located at the rear of the barrel. Cartridges are held in a storage device called a magazine. When the pistol is fired, the slide moves to the rear, ejects the empty case, and usually cocks the pistol. On its return movement, the slide picks up a cartridge from the magazine and pushes it into the chamber.

To Unload Semi-Automatics:

Hold pistol in right hand.
Activate magazine release, and remove magazine from gun. (Magazine release locations vary - consult instruction manual or knowledgeable individual.)
Grasp rear portion of slide with left hand, and move slide completely to the rear, ejecting the cartridge from the chamber.
If the pistol has a slide stop, use it to keep the slide open.
Inspect chamber to be sure it is empty.

Extracts from the National Rifle Association web site for A Guide to Firearm Safety