This is a guide on how to install CFW on v3 PSP 2000 and 3000.

Here's what you'll need:

A PSP running ChickHen R2

A computer

Here's the guide:

Step 1: If you have a PSP running ChickHEN r2, then skip this step.

Step 2: Download 5.03 GEN-A CFW here:
[Only Registered users can see links . Click Here To Register...]
2a: Extract files to your desktop.
2b: Connect your PSP.

Step 3: From the extracted files execute the application, LAUNCH-ME.EXE (GUI). You will need a 2.0 .NET Framework in order to run this application.
3a: If you don't have the appropriate .net framework, download this:
[Only Registered users can see links . Click Here To Register...]
3b: Afer download, install the .net framework into your computer. You'll be able to launch the above application.

Step 4: From the application window, choose your PSP model (PSP 2000 or PSP 3000)
4a: On the Mode button, choose option FULL.
4b: On the PSP Drive button, type in the letter of the recognized drive that the computer reads on the PSP. Say e.g. G, H, I, mine is recognized as J.
4c: On the PSP Install button, click option YES.
4d: Lastly, click Start and the files will be copied into your PSP.

Step 5: Go back to your PSP and go to GAME and launch main EBOOT.PBP.
5a: The application loads and you will either press L or R button (I used L).
5b: When done, press circle (o) to reboot the CFW. Ta-dah, you now have 5.03GEN-A for HEN installed to your PSP!

Take note that the CFW installed in the PSP's memory not in the flashes so, if you shutdown the PSP, it'll revert back to the original firmware. Don't forget to read the readme.txt that came along with the cfw download.

If you wan't to stick with the CFW, I recommend to use standby mode.