Sorry to say it but you're going to need a pandora's battery. If your PSP is bricked, it's impossible to access the flash0 without a pandora. Once you make one (I recomend the UPMS) then you can either choose to access your flash0 and paste the files or you can simply recover to the firmware it allows you to go to.
UPMS Installer is a CSO file that you run on your PSP. This will only be helpful to you if you actualy have a friend with a homebrew enabled PSP because otherwise, you can't run it.
If you make the pandora's battery then yeah, you press X to recover your PSP to CFW, it should be very straight forward once you're there.
I'm not sure. It all depends on your friend's PSP. Do you know if he has a custom firmware on it or not? If he does then yes you can make the pandora's battery very easily (I may be exadurating just a little bit).
ya he does, so all he has to do is follow a tutorial and make the battery and magic stick, and if i put it in mine it will boot to servic mode and i can unbrick it rite?