Every step should only affect a handful of classes or functions, that you can still keep in your head and easily verify. Basically, same thing as if you were doing it by hand, but at a higher abstraction level, so faster and less mentally tiring.
Shameless plug: I am working on a new cross-platform IDE designed for just this kind of workflow. It has basic C/C++ support already: https://sysprogs.com/CodeVROOM/?features=why