1. Please log into your channel and click Manage.
2. Now click on the Settings tab.
3. Once you've selected the Settings tab, you should see a set of options on the left: please select the Channel Managers option.
To remove the channel manager, Just click on the "Revoke" button.
You will see the below screenshot when the "Revoke" option is selected.
When revoking a user you will be asked for confirmation. Once this is confirmed, the user's access to the channel will be revoked immediately.
For steps on how to add a channel manager, please go to the article link below: