Getting Started
First, make sure you are grabbing a trigger meant specifically for your model and generation. For instance, a Glock 17 Gen 5 trigger is not backwards compatible with a G17 Gen 3 or Gen 4, but many trigger replacements can fit Gen 3 and Gen 4 guns. Just check before you buy.
For this article, I’ll be using a Zev Technologies pro flat-face trigger on my Glock 19 Gen 4.
Related: Zev Tech Pro Flat-Face Glock Trigger Review
Since this Zev Tech trigger wasn’t a completed drop-in trigger group, there are just a handful of extra steps. You get to skip those if you got yourself a full drop-in option. The whole process takes just a few minutes and only requires a punch tool.
New guns can be a bit stiffer, so you can also use an armorer’s block and small hammer for removing pins. But at no point should the process require a lot of brute force.
Step 1: Pins & Slide Stop
Ensure your gun is unloaded. Start by using a punch to push out the locking block pin above the trigger (top left). Then move on to the trigger pin (bottom left). This pin has grooves in it that sometimes make it a bit harder to remove. Use your punch to push it out while wiggling the slide stop (top right) up and down and side to side a bit to help the pin work its way free.
Do not over-force the trigger pin by pounding on it. It’s easy to feel like it’s stuck, but you generally just need to gently work the slide stop free for it to slide out. Once the pin comes out, pull out the slide stop and spring (bottom right).
Now you can also remove the locking block. This part might be tight on a newer Glock pistol. You can use a punch or flathead screwdriver to lever it out until you can finish removing it with your fingers.
Step 2: Trigger Group
Use your punch to poke out the trigger housing pin at the rear of the grip (top left and right). This pin is normally polymer, so don’t overbend it or crush it with pliers. It should push out without too much effort.
Then gently lift out the trigger housing (bottom left). I generally lift the metal ejector with one finger until I can use two fingers to grab the sides of the housing. The entire trigger group (bottom right) should just pluck right out with the housing.
Step 3: Trigger Bar & Spring
If you have a complete drop-in trigger kit, you can skip this step. If you need to use your trigger housing or want to change out the trigger spring, just follow the steps below. My particular Zev Tech trigger only came with the trigger shoe (the part your finger connects with) and the trigger bar (the long metal bar connected to the shoe). I also bought a replacement trigger spring, and I will need to connect all of these to the trigger housing.
The trigger bar has a cross-shaped piece at the back end (left). Gently rotate, lift, and pull back this cruciform to disconnect it from the housing. You can also remove the connector (top right) with a small flathead screwdriver or with a punch. There’s a hole on the other side for the punch to push out the connector.
Finally, disconnect the trigger spring from the trigger bar (bottom right).
Step 4: New Trigger Assembly
Connect your trigger spring to your new trigger bar and the trigger housing (top left). Then rotate the cruciform portion of the trigger bar back into the housing (top right). Slide the connector between the housing and trigger bar (bottom left). Then press it in with your finger.
SPRING NOTE: The trigger spring should make the shape of an S when installed as seen in the image below.
Step 5: Reassembly
Press the trigger housing of your completed trigger group back into the frame (top). Anchor it by reinserting the plastic trigger housing pin (bottom left). Reinsert the locking block (bottom right).
First, insert your locking block pin that is above the trigger pin (top left). The slide lock and spring fit under this pin and into the frame (top right). Now reinsert the grooved trigger pin (bottom left). Again, you shouldn’t need to forcefully pound this piece. Instead, press on the pin and wiggle the slide stop up and down and gently to the side as you work the trigger pin into the frame.
Function Check
All that’s left to do is to pop your slide back onto your Glock and test its function. Ensure your gun is unloaded. Rack the slide. Pull the trigger to the rear until you hear and feel it release the striker. Keep the trigger depressed, rack the slide, and release the trigger. You should hear and feel the trigger reset. Pull the trigger to test the reset.
