Pull off the mattress and bedding from the crib.
Remove the bolts on the side rails with an Allen wrench.
Take out the screws from the front and back of the crib with a Phillips head screwdriver.
Lower the mattress support to the lowest level on the frame.
Bolt the side rails to the backside of the bed to become the headboard.
Bolt the front and back sides of the crib to the foot of the bed to become the footboard.
Place the full-size mattress onto the mattress support.