Alright.. For this i recommend not trying this on a PSPGO.. That's all i have to say, i know it works on a darth vader slim.. But if your PsP Isn't hackable.. Go get a new PsP..

Now you should be on firmware 6.39, and you should be able to boot the device in recovery mode (Hold R as the PsP starts up) And you should see a list of confusing stuff.. Ignore it all for now.. You will have to downgrade! and if you don't have the custom firmware and the recovery mode boot or the confusing list of stuff, it's fine. What you need is:

This file package:

Now you should put your PsP into USB mode and open it to view files by going to Computer / My Computer > Removable Disk..
Drag all the files to the root of the psp, the psp root should look something like


And so on.. Just drag the files into there..
Now that you have the files you need, nice and simple.. just go on your PsP, make sure your upgraded to official firmware 6.39.. Then run HEN.. Once HEN is installed, you will have your USB ports open for the recovery flasher.. Run the recovery flasher, and set the top one to 5.00 or 500.. Then go down one and click X And wait for your PsP to downgrade.. Once it's downgraded, boot in recovery mode (Hold R while the device boots up) and to to Plugins, and make sure Nitepr.prx is enabled.. Then start up Metal Gear Solid Portable Ops Plus, Medal of Honor Heroes 2, or Grand Theft Auto Vice City Stories, The codes i have already loaded onto the files.. Or get your own codes, and make sure they're for NitePR and put the game id as the name of a text file, put the text file into PsP > Seplugins > NitePR and the codes inside the text files. And you're done.