Grasp the bottom edge of the bed frame that the mattress lies on and lift upward on it.
Begin pushing forward on the frame when you have lifted the frame as high as it will go or as high as you can lift it. The bed should begin pushing up into the wall.
Push the bed entirely into the space until it is flat and even within it. Then close the cabinet door to cover it.
Place the bed's pillows, linens and blankets within a trunk or storage cube for easy access when you need to make the bed again.