The key is keeping your weight low and centered.
At the dock:
* Untie the kayak and keep the line in your hand
* In shallow water you can lift your paddle vertically - set one end into the bottom of the water snug against the kayak side steady it. If you're in deeper water lay your paddle within reach and you'll use the dock edge to steady you.
* Sit on the dock edge dangling your legs over and balance the cockpit edge with your feet to line up your entry position - drop the tie line into the cockpit.
* Using the dock edge to steady you, swing one foot then quickly the other into the center of the cockpit - quickly crouch down - then sit.
* Take your paddle in your hand, rest it across the cockpit and adjust the tie line so it won't drag when you paddle.
Upon return, exiting is basically the same in reverse