The Phantom 3 Standard remote controller has a built-in lock that holds the left stick in the full down position. This feature was designed to help make landing easier, but it can be a hassle when flying and/or if you do not like to move the throttle to the full down position when landing. The throttle lock can be easily and safely removed. And, it can be done without permanently altering the remote controller.
Place the remote controller face down on a sturdy surface and use a Phillips screwdriver to remove the four screws on the back of the remote controller.
Gently pry open the bottom of the remote controller and raise it up to about a 45 degree angle. The top of the remote controller will remain attached to the antenna as you're doing this.
Gently slide the base of the remote controller away from the antenna. The base should slide out and away from the antenna and allow you to reveal the contents of the remote controller.
The cables should have enough slack to allow you to lay the base of the remote controller to the side.
Use a Phillips screwdriver to remove the two screws that are holding the throttle lock to the remote controller.
Keep the throttle lock and screws in a safe place -- in case you decide to reinstall them in the future.
Close the remote controller by reversing the steps used to open it. And, reinstall the four screws on the back of the remote controller.