Assemble the bed frame according to the manufacturer's instructions. You can do this with a few simple screws attaching wheels or feet to the bottom of the bed frame, as most metal bed frames come pre-assembled. If the bed frame does not come pre-assembled, simply screw the bolts into place according to the instructions. Assembly takes only a few minutes.
Line up the frame with the headboard. There are two wing-shaped pieces at the top of the frame, designed to attach to the headboard with nut and bolt assembly (included with the frame or headboard hardware). The metal frame has two interconnecting bars. Pushing these bars together makes the frame narrow and pulling them apart makes the frame wider. The bars slide easily in either direction. Adjust the frame until it lines up with the accompanying holes for the headboard you are using.
Bolt the frame to the headboard with the hardware included in the frame assembly. Slip one bolt through the hole in the headboard with the long end of the bolt facing the foot of the frame and the head of the bolt flush with the headboard. Tighten the bolt in place with the nut, first with your fingers by screwing the nut in place and finishing with a screwdriver or wrench. Repeat this process on the other side of the headboard and the frame assembly.