How to assemble bed?

[scuderia]

So got my truck with the bed in pieces and have just scored some original wood and need to start the process of putting it back together. I hear guys say it's best to remove the bed to install the wood so I figure I'm one step ahead.... Then I see photos of what looks like the entire bed assembled but just not on the frame?? Can someone shed a light on the easiest way to assemble.. Thank you