From other source, but not allowed to post urls.
1. Update your PSP To firmware 6.60
2. Install Pro CFW
The Pro CFW archive provides several subfolders in the “PSP/GAME” folder. Two of them are interesting for us: the FastRecovery and the PROUPDATE folders. Those two need to be extracted to the PSP/GAME folder on your memory stick.
Assuming you extracted the files correctly, you will see a few new applications in your PSP’s Game menu. The one you will want to run in order to install Pro CFW is “Pro Update”. Just run it.
That’s it. You can erase the “ProUpdate” folder from your PSP, but keep the “FastRecovery” one.
3. DAILY USE
That’s it, I said 3 steps

Welcome to the world of Custom Firmwares. There’s no additional step required to install the Pro CFW. However, every time you reboot your console, you will have to reactivate ProCFW, which is done by running the Fast Recovery tool from your PSP’s Game menu, and takes literally 5 seconds.