ROM Hack how to modify default banner of gbc vc?

[noctis90210]

can someone help me modifying (not creating) the default screen gbc vc banner?
(literally the screen of violet gbc on the banner)
i already have the banner.bin (renamed it banner.bnr)
opened it via 3ds explorer and exported the banner.bnr.cgfx
extracted the contents of cgfx file via everyfilexplorer and it produced the .dae file together with the pictures with png file extension

im i doing the right track???
or did i miss somthing?

i just want to change the picture showing the "screen" of the gbc vc...
correct me if im wrong, do i need to just edit the png... then rebuild it immediately???
or do i need to change something in any 3d texture editor such as 3ds max or blender? (i thnik no cuz i not going to modify shapes, animation, etc)
just correct me if im wrong...

whats the best png editor to use so that even i edit a certain part of the picture (the screen), everyting will be ok once i make a new screen on that violet gbc on the banner...

and about the text, what is the name of the font used on that?

i also want the default gbc sound "tining!!!" :-) on making the new banner... where can i find it? does it included on the cgfx?

thanks and have a nice day...