Once you are logged into your Adwords Campaign, click on your online campaign. Once it is opened, hover over the campaign and click on the Ads button.
Hover over and select which ad you would like to convert into a mobile ad.
Select copy & edit, a little pop up will appear notifying you that changing the ad will delete the existing ad and create a new one, which will be submitted for review. The old ad’s statistics will be visible in the total line for deleted ads.
Select yes, I understand.
You will need to create a mobile friendly call to action for your new mobile ad and remember to click on the check box next to mobile.
Click save and it should automatically update.