One kick to go sideways, a mixt of the backhop and pedal kick.

Balance and pulse....
° Stay in balance parallel to the step, as close as you can get, good pedal outside (right for me).
1° Start folding backward on the bike to prepare yourself for a jump impulsion. That brings you really behind the seat.	2° Jump, lifting the front wheel like in a back hop. At the same time, boost your impulsion by kicking in the good pedal.	3° The pedal kick sends you off the ground, carry on pulling on the bars and fold up the knees to let the bike take off.
See the move in an animated gif

More tips? You could climb sideways by just using a back hop technique, but it is less efficient. Combining the move with a pedal kick also prevents you from moving backwards. You can even land directly on the back wheel if you insist.

A variant of the side-hop is to move up from a static point, starting in balance with the front wheel already onto the edge where you want to climb. This is probably the second most useful move in time trials riding.