Instructions
Turn on your PS3 system. Click on the web browser option from the main menu.
Input "Multiman game manager" into your web browser. Multiman is just one of many game manager mod downloads available on the Internet for the PS3.
Scroll down the screen until you see the download link. Click on one of the compressed download links.
Select "OK" from the pop-up download box. Select where to save the file and hit "OK" again.
Open the file using a program that can extract compressed files. WinRar and several other open source programs are available for free if you don't already have one.
Select the Multiman icon within your Rar program. Drag and drop the Multiman file installer to your desktop. Click on the installer from your desktop and follow the instructions.