So bassiclly what you need is a custom firmware depending on what ofw your psp is. Say if it is 6.39ofw then you need to get cfw6.39 for example 6.39 pro b 9 <- that is the name of an cfw.
1st. Download the cfw depending what your psp version is right now.3.XX,4.XX,5.XX,6.XX,etc.
2nd. Extract the file using winrar and there should be two files pro update or if it is some other firmware for example mme,etc. And the second file should be fast recovery.
3rd. Place those two files in your psp in PSP>GAME.
4th. Turn your psp on go on game and there should be two new files click on the one that says pro update\mme update go on install and wait for it to hack it.
5th. Enjoy your psp is hacked. If your psp freezes while playing a game don't worry go on fast recovery and it is quicker.
Hope this helped took me long.