Instructions
Download a "Burnout Dominator" game-save from the Internet. There are some trusted websites that supply game-save data, such as GameFAQs and QuickJump. Download the game-save file to your desktop.
Double-click the ZIP file you downloaded to unzip it. A new folder will appear on your desktop.
Connect your PSP to your computer using a standard USB cable. Turn the PSP on and scroll to the "Settings" menu, then put the PSP in USB Mode by selecting "USB Settings."
Allow the computer to recognize the Memory Stick in your PSP, then double-click its icon --- the icon appears in "Computer" for Windows users or on the Desktop for Mac users. Double-click the "PSP" folder and locate the "SAVEDATA" folder in the new window.
Drag and drop the folder you unzipped from the game-save file into the "SAVEDATA" folder on your PSP. Allow the transfer to complete. Disconnect your PSP from your computer and load the game. When asked to load a "Save" file, the downloaded game-save will appear in the list of "Save" data.