Approach the drop slowly with your saddle low. You will be standing but slightly crouched and central to the bike. Your chocolate foot (your strongest foot) will be up and your other foot down. Shortly you will use this foot with the pedal to create the force to raise the front wheel.
As your front wheel comes to the lip, then in one smooth moment you create a slight spring by moving your body froward then back to central whilst pushing down smoothly on your pedal/foot that is up. The front wheel now lifts. it is key to keep the pedal smoothly moving round to ensure your front wheel stays up until you land. It also helps to keep a firm constant force pulling back on the handlebars until the bike drops.
As you land you will be on your back wheel. Release the pressure pulling back on your handlebars and lean your weight slightly forward to bring the front wheel down and pedal off. A tip is to have your back break ready on the drop just to make sure you don't fall backwards once completing the drop. Be sure though not to feather this whilst doing the drop or you would nose dive. /this is a smooth, really useful and fun move.