Can someone give me advise on repairing rusted out floors in my 67 C10.

[oleguy]

I purched new front floor pans, footwells, front cab supports and rocker panels for both sides of my 67 C10. In the past have repaired rust and replaced several rocker panels with no problem. I would appreciate any advice you have to offer on replacing the floor, footwells and front cab support. Before I cut the floor and cab support out do I need to brace the cab and if so how is this done. The cab is up on sawhorses now. All advice will be appreciated.