How-To Replace Rear Frame Rails?

Hi All - Does anyone have a good step-by-step thread on how to replace the rear frame rails by the leaf spring mounts (I need to replace the first 8ish inches on each side).

I've tried following the complete frame off rebuilds but most have a frame rack or several tubes holding the car in place because they removed so much metal. Is it necessary to weld those cross braces in place if I'm removing most of the trunk pan each frame rail, one at a time?

Thanks -

Greg
Author: Zell