Direct on-PSP editing is impossible. Kit data is encrypted in EDIT.BIN / 0_texture.afs / dt0c.img. You need a PC + Custom Firmware (CFW) PSP workflow.
PSP_GAME/USRDIR/DAT/0_texture.afs (kits/balls/faces) or EDIT.BIN (team data)..tm2 / .gim format)..tm2 → .png (GGS / TMO Tool / TextureConverter)..png → .tm2 (Swizzled, indexed color).0_texture.afs via GGS / PESKitServer.EDIT.BIN if changing kit assignments (Home/Away/GK slots).SAVEDATA folder on PSP/SAVEDATA/ → Load in-game → Extras → Edit → Data Management → Load Option File.SAVEDATA first.