Things You'll Need
Instructions
Download the PSP Java application from the resource section of this guide. Connect your PSP to your computer with the USB cable and select "USB Connection" from the PSP main menu. A window will pop up and you will see the files and folders on the PSP memory stick.
Right-click the file you just downloaded and click "Copy." Go into the PSP memory stick from your computer and open the "PSP" folder. You will see a few game folders. Right-click the "GAME150" folder and click "Paste." This will transfer Java to the PSP.
Press the "O" button on the PSP to disconnect it from the computer. Go into the PSP game section of the PSP main menu and you will see the Java application. Select the Java application with the "X" button and Java will be installed on your PSP.