You can remove an agency recruiter from a job via the Job Dashboard.
Navigate to the job (Jobs > Job Name). From the left panel, click Sourcing, then click Agencies.
For each recruiter listed under the agency you want to remove, click the recruiter’s name. (Do not click the Edit icon.)
Click Add/Remove Jobs.
Uncheck the boxes next to the jobs you no longer want the recruiter assigned to, then click Save.