(I TAKE NO CREDIT FOR THIS GUIDE, ORIGINAL POST BY ADMIN_PSP MAD HACKER ON WWW.PSPMOD.COM)

It's happened again, those of you using PSP 3000 can smile again as there's a way out for you.
Davee just created the chickHEN (Homebrew enabler) for you to enjoy.

Intro : Hi in this guide I will show you how to enable your PSP3000 to play homebrew games / applications / emulators. Please note this will work on any PSP SLIM

1. First of all get the file from,
http://www.pspmod.com/forums/downloa, ew-enabler-68/
unzip the files and click on the folder.

2. Connect your psp to the usb. Take note what drive your PSP maps to. now go back to the folder where the files are downloaded and click on go.bat, enter the drive letter of the PSP and then follow the prompts. The batch file will copy all the required files in to the right locations.

3. Your PSP needs to be running PSP Firmware 5.03, to verify what firmware version you are running go to the settings menu on ur PSP (The left most menu) then scroll down to system settings then click on system infotmation your firmware version will be shown here. If you are not running PSP Firmware 5.03 update by going to the game menu, and click on the memory and then run the 5.03 update. Follow the on screen prompts to install the 5.03 firmware

4. When you are running firmware 5.03 go to the photo menu, select the memory card and press X , you should now see a Chickhen folder, click X again, now as soon as the next screen appears hold down the left down button until you get to the bottom picture. If your PSP powers off you need to turn your PSP back on and repeat step 4. It usually takes me 4 - 6 times until it works. You know the hen is loaded successfully when your PSP restarts by its self.

To verify the hen is loaded go to the settings menu on ur PSP (The left most menu) then scroll down to system settings then click on system information your firmware version should read "5.03 Chickhen R2" If it does ready this you can now enjoy homebrew

But beware as soon as you turn your PSP off you will need to repeat step 4

I've done this several times, and it worked
Enjoy!

This is a very good sign in hacking the PSP 3000 its a matter of time we will be palying Ripped ISO's on the PSP 3000 memomrycards.

@Infoseye
I was able to go back to custom firmware without the pandora battery I wanted to buy from you earlier. I just used Hellcat's Recovery Flasher.

I want to know, after installing custom firmware, is there any further configuration required?
I was able to go to the m33 config menu by holding R while I powered my PSP. But I don't know what to do after that.
Thanks