In case you need to make mass changes to a catalog, here is the step by step process:

1. First download the catalog in a csv format.

2. Then make the required changes. Please note that the item number of the item should not be changed, otherwise the system won't be able to recognize the change.

3. After making the changes in the CSV, open the catalog by clicking on the catalog name

4. Then click on Import.

5. Select the file and click on import.