Recompile a custom kernel

[debianista.deb <debianista.deb@gmail.com>]

Hey folks,

I have a big doubt ...
I would like to recompile my custom kernel without always start from 0, I mean I got the files created before (/debian/....) and now I just pretend to add a single Module to my config, do I have to recompile all of it again ? or can I just update the old one ? I use make-kpkg --initrd kernel-image --revision 2.6.****

thanks for now :)
debianista.deb