This tut shows how to update your psp's cfw to 5.50 GEN D3
Tools you need:
1) 5.50 GEN D3 updater DOWNLOAD link
2) a PSP1000,2000
NOTE: I have no responsible for bricked psp do this at your own risk
First download the 5.50 GEN D3 updater and extract that rar file where ever you want
and copy the 550.PBP in to the root of your psp or memory stick
and open the folder PSP "This is the folder that you extract" and open the game folder
and you will see a " UPDATE" folder and copy that and in to ms0:/PSP/GAME/
and disconnect your psp from your computer and run the updater in to the XMB
and choose Enter and you will see a menu and choose the first one and wait until it finished updating and press X
And you are now Finished