Things You'll Need
Instructions
Use a soft cloth to clean your L1 and L2 buttons. If necessary, lightly dampen the cloth. You want to avoid moisture getting inside of the controller, so only perform this if you have significant dirt buildup on your controller.
Use tweezers to try and pluck your L1 and L2 buttons out of the stuck position. This should remedy the issues you may experience as a result of pressing a button too hard.
Use a Phillips screwdriver to open the controller. Disconnect and reconnect the wires attaching the L1 and L2 buttons to the vibration plate. Use a screwdriver to resecure the controller. The controller should now work.