There are four main pieces to a crib. The back, the front and two sides. Depending on the shape of your crib, the back will become the headboard and the front rail will become the footboard. Unscrew all the parts, removing the sides. The back and front rails are all that you need.
Once the crib has been dismantled you will need a standard bed frame, which you can purchase at a bed supply store, a department store or a home improvement store.
Attach the back of the crib to the bed frame to create a headboard. Attach with the screws supplied with the crib assembly or use bolts that come standard with the bed frame. Most bed frames come with bolts, washers and nuts.
You can use the front rail of the crib as a footboard; attach it just like the headboard. If you don't install it properly, it can be a safety issue.