Let me take qq version number 8.8.88.7830 as an example to show you.

1, first open the mobile QQ, and then find the upper left corner, click on your avatar as shown in the figure below:

2. Then select my QQ wallet as shown below:

3. Then select the balance, as shown in the figure below:

4. Then select my bank card as shown below:

5. Then select the bank card, as shown in the following figure:

6, and then select three points as shown in the figure below:

7. Then select Unbind, as shown in the figure below:

8, and then choose to unlock as shown in the figure below:

9. Enter the payment password, and then select OK to unbind, as shown in the following figure: