I know the Xcode document states that to roll back changes in source control you have to copy and paste what you want from the right pane to the left pane but is that really the only way? I feel like I'm missing something.
Copy / paste is the simplest for just one or a few files, but you have more options on the command line. Here's a page that describes git reset and revert among other things. www.atlassian.com/git/tutorials/undoing-changes