questions Longitudinal floor support rear flange disassembly

[Moosieus]

I’m currently working on restoring my driver side floor with the necessary components from Key Parts, build thread for reference.

 

Does anyone have a canonical procedure on how to disassemble the rear flange on the longitudinal floor supports? Pictured below with the Key Parts replacement for reference.
 

Everything else in the teardown process is relatively customary — removing seam sealer, cutting spot welds, etc. This overlap is the only thing giving me serious pause.

There’s a fastener in this hole for reference.

To dump my thoughts: I’m hoping any spot welds are forward of the square-tube, such that I don’t need to pull apart the rear wall of the truck. Hopefully the bolt pictured above is the only other thing I need to remove.

[coheed]

There are 3 spot welds that join the rear box section and the floor brace. They don't all the way through to the layer underneath. At least they didn't on my truck. I cut the spot weld with a cutter, then used a cold chisel meant for body work in between the layers to lift it up enough to pull the brace out.  That bolt is also used to hold the brace in place and needs to be removed to remove the brace.

[Moosieus]

Sweet, thank you for the ref!