I would just take them off and take them to a spring shop. All they do are springs, and there is a reason for that. You give them your springs, tell them what you need and they will make your springs as good as they can be for the application. Should cost you around $300 to have them all done if you pull the springs out yourself. If you don't want to do it more than once let the pros handle it. I did just because i didn't have the time. I would do it again too.
Complete rebuild axle/engine/everything swap in progress:
Parts already gathered for assembly: 2001 Ford 302, 1990 Mustang GT 5.0 ECU and wiring, NP435, NP205, Pair of axles from 04' F350 SuperDuty (Sterling 10.5 Posi rear, Dana 60HP Front-Both Disk Brakes 3.73 Gears), 37" H1 Tires, 9" lift TJ Coils for 2 link conversion in front, Stage 2 Clutch Kit, 3 Row Aluminum Radiator, Chevy Astro Steering box (4" front Stretch), XJ Rear Leaf Springs (6" Rear Stretch), and lots more.