Change wallpaper on devo 12S

Hello
If somebody can explain me how to change the wallpaper on devo 12S and deviationtx 4.0.1 ?

Thanks

i have seen this post who explain how to make it
www.deviationtx.com/forum/custom-skins/2...vo12-wallpaper#23595

but i see the wallpaper in "media" is name devo8.bmp and i have a devo 12S
so i must name my wallpaper devo8.bmp or devo12.bmp or devo12s.bmp
and on last thing, witch must be the size of wallpaper for deco 12S ? 320x240 or 480x272 ?
thanks

it's ok for me now !

i have download the emulator for devo 12S and it's great, i can emulate all i want for wallpaper, toggle
when it was ok, i have made my new library
and i have flashed my new library on my deco 12S
and it's work very well

thanks for your help