Lay the Dewalt DC385 on its left side with the screws in the trigger and handle assembly facing up.
Turn the 5 screws in the trigger and handle assembly counterclockwise with a Phillips screwdriver until they can be removed.
Lift the right half of the trigger and handle assembly off the left half. Note the position of the wires connected to the trigger. Disconnect the wires and remove the trigger from the assembly.
Place the new trigger in the assembly and reconnect the wires, ensuring that the wires are connected to the same terminals on the new trigger.
Place the right half of the trigger and handle assembly onto the left half and insert the 5 screws into the holes. Turn the screws clockwise with a Phillips screwdriver until they are snug.