Take out the pipe located in the pump handle.
How it works...
Screw in (only pipe) into the cushion valve and wait until cushion is soft enough.
Initially shape the cushion (manually, to the needed shape or. e.g. by sitting or leaning on it)
Screw pump to the pipe and suck out the air, until desired hardness is achieved.
To change shape – screw the pipe alone to the valve, wait until cushion gets soft.
Note: do not inflate cushion.
See Video Guides
It's that simple...