Read the whole tutorial before you d anythng.
Ok this tutorial wil show you how to go from 1.5 OFW firmware to 5.00 M33 CFW.This will only work on the Fat psp becasue it is the only one that can get to 1.5 OFW.
First Download
Kxploitpatcher > [ Register or Signin to view external links. ]
Put That in PSP>Game on your 1.5 psp then run it.
That program will flash some of your psps files so you can move onto the next step.
After you have run that you will need to download
M33 Creator>
Also put that in PSP>Game then run it.
It will extract a different file onto the psp.
If you run the other file it will flash your psp to 3.52 M33 (Remember if you switch off your psp while it is flashing you could brick your psp)
Once on 3.52 M33 you can use most homebrews.
Thrid Step
Download [ Register or Signin to view external links. ]
After it is downloaded you will want to start it up.
Once it has started make sure the selection option is on 5.xx then click install chosen firmware.(Remember if you switch off your psp while it is flashing you could brick your psp)
The psp will flash to 5.00 M33 which means you can do pretty much anything on your psp Except play 5.50 - 6.20 games you will need 5.50 GEN-D3 for that.
You will need to put 5.00 OFW in your psp root to do step 3.
5.00-> [ Register or Signin to view external links. ] .
You will need winrar to extract these files [ Register or Signin to view external links. ] .