How to delete psp files without a usb coard?

I was using HBL (half brew light) and I decied to get rid of the files to make room for littleBigPlanet because I just got my psn account to work but the old emulator files and roms are taking up over 900mb of space so I cant. I want to find a way t delete files without using the usb hook up if you could help thanks plz ignore the spelling problems............