With New Customizer you can…
Features:
*install gameboot(placed at root “gameboot.pmf”)
*install wave(placed at root “system_plugin_bg.rco “)
*install coldboot or bootsound(placed at root”opening_plugin.rco)
*install 01-12 , 13-24.bmp (placed at root)
*install font(placed at root “Itn0.pgf”)
*install credits picture(placed at root “name_plate.png” must be 480×272)
http://forums.qj.net/psp-development-forum/168426-new-customizer-v1-released.html