The method for modifying personal information on a Bank of China credit card is as follows:

1. Open the Bank of China app on the desktop of your mobile phone.

2. Next, click where the arrow in the upper left corner of the page points.

3. Then, click Login.

4. After logging in, click on your profile picture.

5. Next, click on Modify Customer Information.

6. In the subsequent page, after modifying the mobile phone number, click Update Now to modify the mobile phone number.