Refinish truck bed wood

[homeboymi]

I bought this truck with a wooden bed that is shedding the clear coat finish. How much of the bed do I need to disassemble to sand and refinish the wood?
All of the bolts and stainless strips are like new. Someone just did a lousy job of staining and clear coating the wood during restoration. It used to look like the orange spots you see before it turned gray.