We followed up with the publisher to find out exactly how the process works, as it had been referred to as both "importing" and "downloading" on an initial info sheet. The short answer: you'll be downloading new versions of your old songs. "Within the Guitar Hero 5 song import menu, gamers will key in their unique ID from the manual of the previous game, pay a small re-licensing fee and then be given access to download the available songs (like DLC) in a big batch," we were told this morning. That's for PS3 and 360; with the Wii version, the songs can be downloaded on a track-by-track basis.
"This is done to bring these songs up to date with enhanced Guitar Hero 5 features like band moments, expert+ drumming (new for World Tour songs) and the new vocal star power. The game reacts to these songs as though they were DLC and are available in the same play modes," Activision explained.
So, you just need the manual (and a decent internet connection). Unfortunately, this means that some second-hand copies of GHWT and Smash Hits can't be used for the process, as they'll either be missing the original game manual, or their previous owner already redeemed the 20-digit code. "These codes can be used only once," a PR rep revealed. "However, once you have downloaded the content, you are free to re-download it at anytime at no extra cost, if you need to make more hard drive or SD [card] space."