Reseting PSP

[Cello]

I am planning to sell my PSP for 400$ to a guy. But he wants me to have it like when you 1st bought it. Like for exmaple.. It ask you for the time. And where everything is all reseted. Not the System>System Default thing. I mean like totally reseted.. Thanks in advance..

[*o*]

reset to factory, pull out battery for a few hours and that should reset the clcok