An actuator on the door is tuned to a handheld remote you carry on your key ring; upon pressing that remote, a "pop" will release/open the door from the latch just enough for you to pull open and access.
this is the most common method.
Truck was sold today [5/19]. I got an offer I couldn't turn down. I had no more need for a pickup so I cut it loose. About to purchase a '14 Jeep SRT8 this week.