This brief article describes how to field strip a Glock pistol. The illustrations depict the disassembly of a Glock model 19, but the same procedure applies to other Glock models too.
Safety First: Before you begin, make absolutely sure the pistol is unloaded, as follows:
Now, with the pistol unloaded, pull the trigger to uncock the mechanism. The pistol cannot be disassembled if it is cocked.
With the pistol unloaded and uncocked, disassembly can now begin. Locate the disassembly latches, right above the trigger on either side of the frame. Grasp the pistol with both hands, one hand on the slide so it can be pulled back very gently, the other hand arranged to pull down on the disassembly latches.
While pulling down on the disassembly latches with one hand, slowly pull the slide back about an eighth of an inch with the other hand. There will be a slight release in tension as the slide reaches the appropriate distance. Don't pull the slide back too far, or the pistol will recock and you'll have to start over again. This is often the most frustrating part of disassembly the first few times, but once you know exactly how far back to move the slide, it goes very quickly.
If everything went okay in the previous step, the slide can now be pulled forward off the frame. If the slide won't move forward, start over with the disassembly procedure.
Now that the slide has been removed from the frame, the recoil spring, guide rod, and barrel are accessible.
The recoil spring and guide rod must be removed next. Grab the center of the spring assembly and pull it out of the slide. On older Glocks, the recoil spring and guide rod are not permanently attached to each other, so you will want your other hand to be prepared to catch the guide rod in case the spring attempts to propel it across the room as the spring tension is released. On newer Glocks, the recoil spring and guide rod are permanently assembled together, thus eliminating the 'flying guide rod' problem.
With the recoil spring out of the way, the barrel can now be removed. The barrel should be sitting loose in the slide at this stage. Just pick it up and take it out of the cavity in the slide.
The Glock has now been completely field stripped. While stripped, you have access to the major components of the pistol for inspection, cleaning and oiling. Glock recommends against further disassembling of their pistols by consumers.
To reassemble the pistol, simply put the parts back together in the reverse order of the disassembly procedure.