Remove the mattress and box spring, as well as bed ruffles or components other than the frame.
Look at the rail that forms the bed frame’s foot. There is a bolt head near the center held in place with a wing nut on the rail’s opposite side. Unscrew the nut. If the frame was in position for a long time, you may need to use a screwdriver and vice grips to get it started, but you'll usually be able to do this with hands alone.
Leave the bolt in place. Find the corresponding bolt head at the bed’s head and remove its wing nut.
Pull the wing nuts out of their holes.
Pull the two sides of the frame apart, and then fold the loose ends of the head and foot rails into the side rails. This action is similar to closing a pocketknife.
Attach the loose bolts and nuts to the frame with a swatch of packing tape. This makes them easy to find when it's time to reassemble the frame.