After upgrading Apple 5S to IOS10.3.1, the name and phone number in the APPLE ID in settings are grayed out. What should I do?

The main reason is that your account is used by too many people. Just change the account password. The specific steps are as follows:

1. Click "Settings" on the mobile desktop.

2. After entering the settings page, click "icloud".

3. Click on your account avatar on the icloud page.

4. Enter your Apple ID password and click "OK".

5. Go to the Apple ID account settings page and click "Password and Security".

6. Click "Change Password" on the Password and Security page.

7. Select a verification method and receive the verification code.

8. Wait for a moment and the verification code will be sent. Remember the verification code and click "OK".

9. Enter the verification code just sent.

10. According to the prompts, enter the old password and the new password in sequence. The new password needs to be entered twice to ensure that the password is correct. Click "Change" in the upper right corner.

11. After "Changing" is displayed above, wait for a while and then change the password.