CFW a necessity for PSP version/Possible to hack PS1classic?

[Dark Kefka]

If I were to modify a PSP WoTL save with modifications to the sprites as well as classes would I need CFW to run said save or could I create the save and have someone with CFW re-encrypt it for me?  Also, if the latter is what is needed, does anyone on here offer said service?

I own both a PSP 1000 (no longer CFW thanks to a OFW update via my girlfriend   ) and have the PS1 Classic version of FFT on both, is there a way to modify those saves with custom changes?