For your firmware (OFW 3.80) the only way you can flash over to a CFW is to use pandora
The applications for the memorystick are the files you need so that the PSP can boot from the memory card (bringing you into the pandora menu), instead of from the battery, but you also need a pandora battery.
... and from my opinion i wouldnt go to downgrade id rather flash over directly to an updated CFW with pandora


