All you need to do is copy the following files from the old MacOs computer:
~/Library/Application Support/Sublime Text 3/Packages/User/Package Control.sublime-settings
~/Library/Application Support/Sublime Text 3/Packages/User/Preferences.sublime-settings
Also make sure you find the old email with the license you purchased, and make note of the disabled packages, as those may not be disabled when you restart the app with the new config.
Then on the new MacOs:
- install the ST3
- install PackageControl
- Copy the files over to ~/Library/Application Support/Sublime Text 3/Packages/User/
- Restart the application
- NOTE: You may have to restart it a few times, it can be buggy until the config reinstalls all the packages from the .sublime-settings files.
You don't need all the settings packages in the User directory, those will automatically be reinstalled on restart. I guess it wouldn't hurt to grab them all, but usually new Mac == new settings. The "Package Control.sublime-settings" will automatically install all the packages listed in it.
I am about to migrate Macs, I will update this when that is completed to verify it works!
This is also answered in the Apple Stack overflow.
https://stackoverflow.com/questions/11365948/how-to-save-restore-sublime-text-2-configs-plugins-to-migrate-to-another-compute/62581108#62581108