Remove old certificate (debian)?

Question

Debian

Good afternoon.
I just can’t find how to remove the certificate, Google basically shows how to “mute”, but I would delete it normally and request a new one, everything works on new machines.
the server on debain 5
has a lot of files in /etc/ssl/certs, it is not clear which one to delete.

site:~# curl -Iv https://***.**/***
* About to connect() to *** port 443 (#0)
*   Trying ***... connected
* Connected to *** (***) port 443 (#0)
* successfully set certificate verify locations:
*   CAfile: none
  CApath: /etc/ssl/certs
* SSLv3, TLS handshake, Client hello (1):
* SSLv3, TLS handshake, Server hello (2):
* SSLv3, TLS handshake, CERT (11):
* SSLv3, TLS alert, Server hello (2):
* SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
* Closing connection #0
curl: (60) SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
More details here: http://curl.haxx.se/docs/sslcerts.html

curl performs SSL certificate verification by default, using a "bundle"
 of Certificate Authority (CA) public keys (CA certs). The default
 bundle is named curl-ca-bundle.crt; you can specify an alternate file
 using the --cacert option.
If this HTTPS server uses a certificate signed by a CA represented in
 the bundle, the certificate verification probably failed due to a
 problem with the certificate (it might be expired, or the name might
 not match the domain name in the URL).
If you'd like to turn off curl's verification of the certificate, use
 the -k (or --insecure) option.

Answer 1

Are you sure that you need to delete the certificate, and not add it to the certificate store? Is the https://***.**/*** server certificate chain signed with a public root certificate?

Answer 2

Look in the apache/nginx/whatever configs to see which key and certificate are being used.