A daunting task, rear cab support advice please.

[oldarky66]

After about two years of disassembly, and collecting parts,(due to budget restraints and slothfullness) I am finally working on my truck. Frame has been stripped and POR15ed, and now I am tackling typical repairs on the cab. The rear cab support is giving me fits. I've used the search box but seem to only get 70's models come up. Does anyone have this removal and replacement documented in their build that I could reference? Any & all advice or tips will be greatly appreciated.