Things You'll Need
Instructions
Log in to your PSN account from the PS3 home screen menu.
Launch the PlayStation store from the XMB (Xross Media Bar).
Select "Add-Ons" from the PlayStation store menu.
Choose the icon that is shaped like a controller and disc (the first one on the list). This will allow you to view the add-ons for disc-based games.
Scroll through the list of games and select "Rock Band." This will bring up a list of all the available content that can be downloaded for the game.
Scroll down past all the song tracks to the bottom of the list and select the option labeled "Song Export Key." You will then be asked if you wish to purchase the song export key for $4.99. Choose "Yes" to start the download.
Install the song export key after it is finished downloading.
Insert the "Rock Band" game disc into your PS3. After the game loads, you should notice an additional option labeled "Export Songs" on the options menu. Select this option to move all the "Rock Band" songs on to your systems hard drive so you can play them in "Rock Band 2."
Swap out the "Rock Band" disc for the "Rock Band 2" disc. All the the songs from the original "Rock Band" should now be available for you to play on the "Rock Band 2" song list.