How to make a graphic mod

How to Edit the original “graphics.drs” and “interfac.drs” to moddify pre existing building or units graphic ? Or to make my owns.
What kind of programs or sollutions could i use to do those things ?

Thank you

definitive edition doesn’t use those files.

use turtle pack to view/modify .drs.

if you could specify the game and maybe the units you wanna mod, its easier to give an explanation.