The wood will not slide out on the sides under the angle strips. The studs go from the angle strips through the wood and then through the bed cross sills. And the stud in the corner by the cab goes frome the angle strip through the wood and then through the headboard. Stud in the corner by the tailgate goes from the angle strip through the wood and then through the rear cross sills (footboard). So without total disassembly of bed the boards on the sides are going to pose a problem without cheating. You can probably snap and bust the old wood out of there. But to replace it without bed disassembly your either going to have to remove the studs from the angle strips and replace with carriage bolts or notch the wood where the studs are and slide it in.
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