We started on the obvious parts. the tongue and supporting beam. The Jack was undamaged but very, very securely attached to the frame. A clean cut would require more than a mere plasma cutter.
The primary Support beam (Ibeam) was twisted and bent beyond repair I cut it off the main trailer and removed the jack, which we could reuse.
My handy Makita Sawzall was almost as helpful as the wonderful plasma torch
Flipping the whole rig upside down really helped us see what was damage and needed repair.