Hey ya, im posting here a gameboot flasher for all psp's (Using Hen and CFW), including the 3k (3000).
INSTRUCIONS:
1. Unzip the Gameboot flasher to your HomeBrews directory.
2. Inside the Root Folder of your GameBoot Flasher, unzip a gameboot (just one).
3. Now, start your homebrew that will flash the GameBoot.
4. Press the button for flashing the 'PSP GAMEBOOT' AND NOT THE 'SONY GAMEBOOT'
5. After completing, it will ask you to shut down your PSP. So, just shut it down.
6. Be happy with your new GameBoot.
PS: I flashed my PSP with a sword and blood game boot. It Worked really fine !
WARNING: SOME GAMEBOOT MAY BE CORRUPTED. AND WHEN YOU INTALL IT, IT DOESNT START ANY GAME OR HOMEBREW, IT WILL AUTOMATICALLY SHUT DOWN YOUR PSP.SOME GAMEBOOTS MAY DISABLE YOUR HEN.
Here are the links.
gameboot flasher
GamebootFlasherv2.00.zip
link for gameboots
CustomPSP.de ...because your handheld deserves it!: Downloads
IF SOMETHING GOES WRONG

. pass another gameboot to the root folder of the GamebootFlasher Homebrew.
. go to GameBoot Flasher in memory stick but don't press X
. hold down the screen brightness button until screen is off
. Press X
. Wait a while (6-10 sceonds)
. press screen brightness again to turn screen on
. Install the other gameboot
. be Happy :3

I'LL POST A VIDEO SOON, I FORGOT MY PSP AT A FRIENDS HOUSE. XD~