To remove a “LetsEncrypt” certificate, perform the following steps
-  Run the 
certbot certificates commandto list the certificates that exist. -  Run the revoke command with the certificate name, such as 
certbot revoke --cert-name=xxx.com. -  Finally, run the 
revokecommand specifying the certificate name, as in certbot revoke –cert-name=xxx.com. When prompted, type Y to delete the certificate file.