Whether your glock has jammed or you just want to clean it, you'll need to disassemble it first. There are many safety issues that must be considered when handling your glock, and especially during disassembly. All glock models can be disassembled the same way. Knowing your gun is important for safety, so practice disassembling and reassembling your gun as many times as it takes for you to become familiar with its workings.
Glock Safety First
Make sure your glock is not loaded. On the butt of your gun is your magazine; remove it. Now rack your slide several times to ensure there are no rounds in the chamber. After you are sure there is no ammo in your gun, gather all the ammo and take it to the next room or lock it in your gun safe. Even when you are sure that all the ammo is out of your gun, mistakes happen and you will still need a backstop (safe place to aim) when you disassemble a glock. One step in the disassembly will require you to pull the trigger, and it could be dangerous if you missed a round left in your gun. One effective backstop is a five-gallon bucket filled with sand. You could also use bulletproof armor if you have it.
Disassembling Your Glock
Hold and pull back your slide about an eighth of an inch. While holding your slide in place, lower the take-down lever (located above the trigger on the left side). You will feel the slide get loose. Gently pull the slide the opposite way you were pulling back on it. Move the slide off of the barrel end of your glock, and set the frame aside.
Look at the undercarriage of the slide; the recoil spring is located there. Remove the recoil spring by gently adding pressure to one side and lifting it out. Wear safety goggles and be careful, as the spring may pop out towards you. Turn the slide upside down, over your hand and let the barrel drop into your palm. Your glock is now disassembled and ready to clean or troubleshoot a jam.