Step 1: Download the files below based upon what model you have.
PSP 1001/2001: http://www.mediafire.com/file/ei8k5fe39h51q21/release_661me2.3.zip
PSP 1001/2001 OFW Version: http://www.mediafire.com/file/bltluxb06v5l1kz/release_661me2.3_%28OFW_Version%29.zip
PSP 2000V2/3001/Go: http://www.mediafire.com/file/pv333tquf5qu0ac/release_661lme2.3.zip
Step 2: Once you've dowloaded the selected files be sure to update your PSP to 6.61 Official Firmware.
Step 3: Extract the files to a folder and you will see the files stated in the video.
Step 4: Plug your PSP into USB mode and select the drive on your computer and go to the directory on your Memory stick (System storage if using Go) as the following ms0:/PSP/GAME (PSP GO ef0:/PSP/GAME
Step 5: Copy the Installer and Launcher folders to the PSP GAME Folder and exit USB Mode.
NOTE: If you want to install the LEDA PRX just copy the PRX to ms0:/seplugins and use your VSH.txt and type ms0:/seplugins/leda.prx 1 and enable the plugin via recovery menu later
Step 6: Run the Installer on your PSP from the game section and press X in the installer to Flash CFW files.
Step 7: PSP 3000/GO ONLY : set all your settings in your recovery menu and VSH menu and run the Launcher app and your done.