Need to modify Apache sources

I use Apache 1.3.37 and I need to use a bit modified Apache's suexec utility. I.e. I need to modify suexec.c and recompile it. How I can do it? Is Apache sources saved on HD or it downloads every time again?

I wanted to recompile suexec.c myself but now I suppose that you (WHM) modify suexec.c too, so my suexec binary may not work. Am I right? May I recompile myself and successfully use suexec.c from original Apache distribution?

If now, I wait for your help on how I can modify suexec.c before compilation.

Thank you.