Slide one rail into the grooves of the headboard (A), Make sure the slat rail is facing the inside of the bed. Repeat this process with the other side rail. Next do the same with the other end of the rails into the foot board (B). Then tap the top of the rail ends gently with a rubber mallet to make sure the connections are secure. FOR FULL / QUEEN BEDS FORKING SIZE BED Attach the drop support(s) to the center support(s) by placing the barrel nut into the hole in the side of the drop support.