Here is an easier option for you. Upgrade your PSP to official firmware 5.03. NOT any higher, exactly 5.03. Here is the file:
RapidShare: Easy Filehosting
Rename the file to EBOOT.PBP and place this in a folder called UPDATE in your GAME folder. So X:/PSP/GAME/UPDATE/EBOOT.PBP. Then just run it from your PSP.
Then get the 5.03 ChickHEN exploit and enable it as instructed in the readme:
ChickHEN Homebrew Enabler R2 Download
Once you're running in the HEN environment, run a program called Hellcats Recovery Flasher here:
File Details-Recovery-Flasher-v1.41-PSP -
Again, read the included readme for instructions. Make sure you have a copy of the 5.00 official eboot on the root of your memory stick, and flash 5.00 M33-3 onto the PSP.