Why? Hell, grab the plasma cutter, the wizzer, the sawzall and the mig and let's go!
Seriously though, measure twice, cut carefully, and don't panic. You can always fix it if you make a mistake.
By the way, you should have seen the look in my father's eyes when we cut his '56 BelAir in half! But hey, it came out just fine. If I can do it, you can too!
Good luck!
Shiny Side Up!
Bill
'72 442 "Inamorata"