How to activate the Nexus 5X on US Cellular 4G LTE

The following assumes you already own a phone on US Cellular and just purchased the new Nexus 5X from the Google Store. Your existing phone will need to have a SIM card that supports 4G LTE.

1. Turn on the new phone and go through the introductory screens to transfer your Google account and settings from the old phone to the new phone.
2. From a landline, someone else's phone, or Google Hangouts dialer, call US Cellular at 1-888-944-9400 and ask for technical support.
3. Tech support will instruct you as follows:
1. Read to them the "IMEI" number on the sticker on the back of the Nexus 5X.
2. Turn off the new phone;
3. Remove the SIM card from the old phone;
4. Put the SIM card in the new phone;
5. Turn on the new phone;
6. Dial *228 and wait 90 seconds;
7. Turn the phone off, and then back on again.
4. That's it. It should all work now.