1. You need to bring all relevant documents and materials, including your ID card, household registration book, one-child card, etc.
2. Go to the public security bureau where the household registration is located, explain your situation to the staff and submit relevant documents and materials.
3. The staff will verify your identity information and make relevant modifications. This process may take some time, so you need patience.
4. After modification, you need to obtain a new one-child certificate to ensure that your certificate information is correct.
It should be noted that some problems may be encountered in the process of handling, such as the need to provide more supporting materials. If you encounter difficulties, you can consult the staff, who will provide you with help and guidance.
In short, if your only child certificate is written with your mother's name as an alias, you need to go to the public security bureau where your household registration is located to correct it. This process may take some time and patience, but as long as you follow the prescribed procedures, you can successfully modify the certificate information.