Final answer:
To edit WorkstationGPO's audit policy on CorpDC, navigate through Computer Configuration to Security Settings under Policies and enable 'Force audit policy subcategory settings' within the Local Policies security options.
Step-by-step explanation:
To complete this task, the You needs to navigate to the Computer Configuration section within the Group Policy Management Editor. Once there, they should follow the path to Policies > Windows Settings > Security Settings > Local Policies > Security Options. In this location, they will find the option to 'Enable Audit: Force audit policy subcategory settings (Windows Vista or later) to override audit policy category settings' which they need to enable as per the instructions.