How to change the card of Telecom 4G?

The following is the card replacement process:

Card replacement preparation: Please insert the special card for 4G self-service card replacement into Tianyi 4G mobile phone, and insert the original UIM card into Tianyi 3G mobile phone, while keeping it on.

Edit the short message "HK mobile phone number" to 10659 157 with 4G mobile phone to obtain the verification code of the supplementary card (note: the mobile phone number is the original user's mobile phone number).

Check the verification code on the original 3G mobile phone, edit the short message "YZ verification code" to 10659 157 on the 3G mobile phone, and wait for the short message with successful card replacement.

After receiving the SMS message of successful card replacement, restart the 4G mobile phone, and the original UIM card will be invalid.