Plug the vacuum pipe into the main hose of a vacuum cleaner. Make sure the pipe attaches tightly so you don't lose suction once you turn on the vacuum.
Press the end of the vacuum pipe firmly over the memory foam block or pillow so the foam forms a seal around the piping. Turn the vacuum on full power.
Lift the memory foam slowly by elevating the vacuum pipe. The suction holds the memory foam in place if it isn't too heavy. Slowly rotate the pipe to put the memory foam in a different position than what it is currently in.
Turn off the vacuum cleaner once you've rotated the memory foam to your liking. The piping detaches from the foam immediately, but the indentation will still be there partially until you restructure the foam or lay down on it.