Change gapi.php class to work with oauth instead of authsub

There is a class online called [login to view URL] you can google to find it. It is a simple class that connects to google analytics and allows you to pull google analytics data using php. The problem is it uses authsub. Google will discontinue authsub in 2015 so I need the class to work with oauth which is the latest way.. can someone modify the class to work with oauth