Electric solenoids installed inside the door activate the door latch. Some put a button under the rocker panel (or elsewhere) and tap with their foot to operate the solenoids. I have mine wired to an alarm system remote. There are also poppers which push the door outward once the soleniod has unlatched lock mechanism. I have two hidden buttons in case the remote or alarm fails. And, if all else fails, I have hidden a pull cable to unlock the one of the doors.