You must first make sure that you have set up the goal properly in Analytics via this article: https://mongmetrics.zendesk.com/entries/98643346-Google-Goal-Setup-For-Mongoose
Once that is completed you can follow this article.
1.) You will be able to then import the goal into AdWords. Select "Import from Google Analytics".
2.) Click "Import". After you have imported the goal, you will start seeing the conversions in AdWords.
3.) The integration is complete. Mongoose Metrics phone call data that was imported into Google Analytics is now visibile within Google Adwords.