How To: Adjust Sliding Glass Door Lock & Handle 

Tools required: Putty knife, screwdriver, safety glasses and gloves.
We're going to show you how to adjust the lock and handle on your Milgard sliding glass door.
The snib releases and unlocks the door. Once you know how that works, you'll want to check the strike plate. You can move it up and down if the door does not work properly and mis-aligns with the strike plate.
On the snib, the engagement tongue must run into the Milgard logo. If above or below the logo, the lock will not engage.
Using a putty knife, remove the strike plate to expose the adjustment screw. use a screwdriver to back out the screws (located above and below). The strike plate can move up and down accordingly. Once in proper alignment, re-insert the screws.
Double check your lock once this is in place.