- Open your Settings app.
- Click Apps.
- Look for Google Play Services.
- Click Google Play Services.
- Click the Force Stop, Clear Cache, and Clear Data buttons, in that order. Hopefully they will gray out. If not, go around again several times. Eventually they should all gray out.
- When all three buttons are grayed out, go on to the next step.
- There should be a button labeled either Uninstall or Uninstall Upgrades or Uninstall Updates. (Note that the option might be tucked away under a "..." button.) Click it.
- After the uninstall is complete, open the Google Play Store app and install the Google Play Services app. It may be the same version as you just uninstalled, but that's okay; the point is that it was installed from a clean slate.
- If you have trouble finding it in the store, go to this URL in a web browser and you should be directed to the correct app: https://play.google.com/store/apps/details?id=com.google.android.gms