the Health and Lives images are located in languagebank\english\gamecore\huds
place your own custom Health and Lives images there but name them something else, then open up setuplevel.fpi located in languagebank\english\gamebank\mygame and find these lines:
:state=0:hudreset,hudx=5,hudy=5,hudimage=languagebank\english\gamecore\huds\[b]lives.tga[/b],hudtype=1,hudmake=display
:state=0:hudreset,hudx=15,hudy=5,hudimage=languagebank\english\gamecore\huds\[b]health.tga[/b],hudtype=2,hudmake=display
replace the fields I marked with the name of your custom images and change the hudx and hudy if needed.
That's how you change the huds