the picutures have to be 64x64x8 bmp and you use the
Custom xmbIcon Packer to convert the pictures to an .rco file. Then use
Xflash v18j to flash them to your psp. Put the .rco file in the Xflash Modified folder. Run Xflash and go to option 14, press left once, then hold X + Right & Left and it with flash it if the .rco file is the correct size and all that.