This is a guide and neither Techkings nor I accept any responsibility for any damage caused to your PSP!! First off you need a pandora battery HERE and a memory card HERE. you don't have to buy them from Deal extreme, they are just someone that I have used and found them good(but a little slow). I do this in three stages, and it works for me, it probably can be done in less steps, but hey. you must down load this from mega upload DOWNLOAD, i t contains three folders and they correspond to the three steps below. Step one: in this step you will create a magic memory stick, which will downgrade your PSP to 1.5 run the rain mms program and this is what you will see Instructions: Have your PSP connected and in USB mode. 1) Extract the 380.PBP and Rain MMS program. 2) Run the Rain MMS program and select the following. 3) Select 3.80 OFW/M33-5 (DCv4) and click load Eboot, and select 380.pbp (downloaded file) 4) Your PSP should be detected at this stage already, check the "format memory stick" box. 5) If you have a Phat PSP then you can select "1.50 Kernal addon installer" Just under the checked box USB version fake plugin. I repeat if you do NOT have a Phat PSP then do not select the 1.50 kernal add on otherwise you will fry your PSP!! 5) You can leave the defaull trigger button to L(Default). 6) Finally, you can now select "Make MMS", at this stage the program will format your memory stick and create the necessary index with all the files required for the downgrade. 7) Disconnect from PC and remove any batteries inserted in the PSP, and put in the memory stick. 8) Press and hold the "L" button, Carefully put in the pandora battery, make sure it is not taken out until the process is finished. 9) The green light should now come on before (as tested earlier), aswell as the red flashing memory stick light. If the memory stick light does not come on then that means there was a fault in making the memory stick, so you will have to repeat the steps again. 10) The PSP should now display some white text, from memory, you will have to press "X" to install the 3.80 Custom firmware. 11) The downgrading will now begin, alot of text will appear on the screen, rushing down. But dont worry, this is supposed to happen. 12) You will know when the downgrade is succesful when the PSP tells you so!, it will say the downgrade is successfuly press "X" again to restart your PSP 13) Congratulations, you now have a PSP with custom firmware. step two: open the step two folder and put the UPDATE Folder IN PSP/GAME Folder on PSP. Now go to the PSP, Go into the games section of the memory card, and it will be listed there with your other games. Just hit X on the Update icon and away you go. Step 3: In this step you will install the latest custom firmware version to your PSP - Connect your PSP to your computer using the USB cable. - Copy the "UPDATE" folder into /PSP/GAME - Copy the "550.PBP" file into the root of the memory stick(memory stick first page) - Exit USB Mode And run the "5.50 GEN-D3" from GAME section.. - Press "X" for Enter - Select "Flash Install CFW 5.50 GEN-D3" and Press "X". Start install.. please wait. - When install completed press the "X" button to restart automaticly.. done.. - Look at the version : System settings > System informations > Version : 5.50 GEN-D3 - Now..You have to backup your files(high scores, Games, movies, etc.).. And format memory stick from psp "system sttings > format memory stick.. - Now .. Check all your recovery settings.. Configuration > UMD Mod (currently : Sony NP9660 -NO UMD-) Use VSHMenu (Currently) : VSHMenu Use version.txt (corrently) : Enabled CPU Clock XMB : 222/111 or Default CPU Clock GAME : 222/111 or Default - And Play the games.. Thanks must go to Dan-Ger-Ous for his help with this Tutorial. he helped me out when i first tried to put custom firmware on my PSP and this guide has evolved from the thread when I was looking to upgrade my PSP. If anything is incorrect here or you think that i should add anything to this tutorial, then just let me know.