How to bulk delete email aliases of the users created on secondary domain

[Cloud Admin]

Hi Workspace admins, 

I am writing this to get the guide how can I bulk delete the email alises that exists on the seondary domain. I got to know that GAM can be used to perform this task. 

I am new to GAM and know about it how to use it. So I need your support to accomplish this task. 

I didn't install GAM yet even don't have any knowledge about it. 

Your guidance in this matter is highly appreciated. 

Best,