Using a browser on your computer or laptop go to "play.google.com" and login with the email address linked to your play account
1. In Google Wallet change your address to a US one.
2. In Google Wallet delete all your payment methods and add a USA credit card with a USA billing address.
3. NOW here is the Open Sesame Code....
4. In Google Play create an order for anything but do not complete the purchase.
5. At the final "Approve your order screen", STOP, an leave this screen up for at least 30 minutes. Do not complete the purchase.
6. Clear your browser cache.
Have someone with a US phone install the app, then back it up with an app (like App Backup & Restore) that backs up to apk files. Transfer that apk file to your phone and run it.