How / if to refactor a Delphi program using only forms and data modules

Question

After years of coding Delphi programs as untestable code in forms and datamodules, including global variables, and the only classes are the forms themselves, containing all

Answer 1

Another book I can highly, highly recommend - in my personal opinion even better suited than the "generic" refactoring book by Fowler - is "Working Effectively with Legacy Code" by Michael Feathers. It truly showcases the major bumps you will hit while doing that kind of work. Oh, and: Refactoring legacy code can be quite hard on your psyche. I hope you can handle frustration... I like this quote (don't remember where I got it from): "God was able to create the world in 6 days, just because there wasn't any legacy code". Good luck. ;)