Go to your Job Agent Overview. Click ‘Remove’ for the Job Agents you wish to delete. Once you have done this, a pop-up will appear asking you to confirm that you indeed wish to delete the Job Agent. Another way to do this is to click unsubscribe in the e-mail containing the jobs that you receive.
Note that if you delete a Job Agent and want to start receiving it again with the same criteria, you will have to create it again from the beginning.