Product Research is a market analysis tool under Alibaba Group. It helps merchants analyze product categories, keywords, competitors and other information. If you want to modify the competitive categories in Product Research, you usually need to follow these steps:

1. **Log in to Product Research**:

- First, log in to your Product Research account.

2. **Find competitive categories**:

- In the Product Research interface, find the section for managing competitive categories. This may be in the "My Store", "Market Analysis", "Competition Analysis" and other sections.

3. **Select Modify Category**:

- In the list of competitive categories, find the category you want to modify.

4. **Edit Category Information**:

- Click the "Edit" or "Modify" button to enter the editing interface.

- In the editing interface, you can modify the category name, description, attributes and other information.

5. **Save changes**:

- After completing the changes, click the "Save" or "OK" button to ensure that your changes are saved.

6. **Check the results of the changes**:

- After the changes are completed, check whether your competition categories have been updated to ensure that the changes are effective.

Please note that the specific operations of Business Advisor may change with the version update, so it is recommended that you check the latest official tutorial or contact Business Advisor's customer service for help. In addition, modifying the competition category may affect your market analysis and competition strategy, so before making any changes, please carefully consider and evaluate the potential impact of the changes.