Board Thread:Questions and Answers/@comment-174.65.37.143-20131114035810/@comment-216.165.220.19-20140130162130

If you're on a mobile device, go to the Google Play store, slide your finger across the screen, left to right, this will bring up a menu. Click 'Redeem', and enter your code.

If you're on a pc, log into your Google account and go to https://play.google.com/store, after, click redeem on the left menu and enter your code.