Mobile service password, what SMS does the mobile phone send to reset?

Take Apple 6 mobile phone as an example, the method is as follows:

1. Open the information on the mobile phone desktop, as shown below.

2. After entering the information, select the icon in the upper right corner, as shown below.

3. The recipient should fill in 10086, as shown below.

4. Fill in the reset service password in the letter column and send it, as shown below.

5. Fill in 40+ new password+ID number and send it, as shown below.