If you want an extension to June 15, just print your return, file by mail, and attach a written statement explaining your circumstances.
If you want an extension to October 15, you must request that in writing (not electronically). Print a copy of form 4868, complete and sign it, attach a written statement explaining that you are living overseas, and make sure it is mailed (postmarked) by June 15. You may want to use a mailing or express service that has tracking and proof of delivery.
