how to authorize mac on itunes

I put the Mac system on a 128G SSD SSD, the results found that my User name folder has more than 20 g of unknown files, but also show that I would like to save some space on the SSD, I would like to use these potentially useful files to my 250G mechanical hard drive.Enter "Go to Folder" via Shift+command+g [~/library/application support], go to this hidden folder, a sub-folder to look over, Found the culprit is a folder called Mobliesync

1. Copy an app in the application list rename to Donothingapp.app (non-system app can replicate successfully) 2. Open Terminal execute the command (you will need to enter a password after execution), note that the MV and Itunes.app have an English space respectively: sudo mv/applications/itunes.app/applications/itunesback.app3.terminal executes the command, noting that the-R and Donothingapp.app each have an English space: sudo cp-r/applications/donothingapp.app/applications/itunes.app