I've created a How To on my blog showing how to downgrade from iTunes 11 to iTunes 10.7. It also includes a link to download a copy of iTunes 10.7 if you need it.
http://www.emacconsulting.com/apple/itunes/downgrade-itunes-11-to-itunes-10-7/
I'll post it here too.
1) Open Terminal and run:
sudo rm -rf /Applications/iTunes.app
This will delete the iTunes 11 application.
2) If your Music Library is in its default place, also in the terminal:
open ~/Library/Music
3) Using Time Machine restore the following files:
- Album Artwork <– Folder
- iTunes Library
- iTunes Library Extras.itdb
- iTunes Library Genius.itdb
- iTunes Library.xml
- iTunes Library.itl
- iTunes Music Library.xml
- Previous iTunes Libraries <– Folder
No need to replace your iTunes Music Folder.You may not need to replace all these files but it can’t hurt.
4) Back in the terminal:
open /System/Library/PrivateFrameworks
Use Time Machine again to restore the following files:
- AirTrafficHost.framework
- CoreFP.framework
- DeviceLink.framework
- iTunesAccess.framework
- MobileDevice.framework
5) Download iTunes 10.7
http://appldnld.apple.com/iTunes10/041-7195.20120912.d3uzQ/iTunes10.7.dmg
6) Install iTunes 10.7.
I rebooted for good measure, but it’s probably not necessary.
You may be prompted the first time you start up iTunes 10.7 for your password. Enter it. You should now be able to do all the things you need, including syncing your iDevices, without the nasty iTunes -42408 error many people have been getting before this method.
Enjoy iTunes 10.7!