Modify the file "Pcl3Gui2.cpp" in the installed HPLIP

Hello,

I have modified the file "prnt/hpcups/Pcl3Gui2.cpp" in the following package:
https://sourceforge.net/projects/hplip/files/hplip/3.19.6/hplip-3.19.6.tar.gz/download

Question:
Instead of installing the whole HPLIP inclusive the modified "prnt/hpcups/Pcl3Gui2.cpp" new, I would like to implement my change more directly.

How:
For example something like edit some files in the already installed unmodified HPLIP on my system.
Or by making a patch I can start. And this patch makes the change in my already installed unmodified HPLIP on my system.

Would this be possible?

Would appreciate some reply. Thank you.