To remove an agency from your organization's Community simply take the following steps:
Find a candidate submitted by the agency you want to remove, click on that candidate's name to open their card.
Then go to the "Chat" tab on that candidate's card.
Click on the Agency Recruiter's name at the top of the conversation (see below), this will open the Agency Recruiter's drawer.
From there click on the action menu located in the top right of the drawer.
Select "Remove from Community" and then confirm their removal by submitting the form.
Note: Removing an agency not only removes the individual recruiter but their whole team