In order to remove a certificate, go to the ‘Security Policy’ page (Start Page > Admin > Security Policy) and find the certificate you are looking to remove, click on it to bring up the policy details.
With the certificate highlighted, click the ‘Delete’ button on the top bar - you will be prompted to confirm this action. Confirming will proceed with the action.
Please be aware that once a certificate is deleted it cannot be restored and will instead need to be recreated.