Issues with Lets Encrypt, Purging self signed SSL certificate.

[Jumpstarter]

How do I purge the old SSL certificate? I am asking because I want to purge the old one so I can generate a SSL certificate using Lets encrypt.

This is what I am seeing inside system logs while trying to switch to lets-encrypt.

Oct  5 19:30:22 kernel: /usr/sbin/acme-client: SSL_connect error: 5: Connection reset by peer
Oct  5 19:30:22 kernel: /usr/sbin/acme-client: https://acme-v01.api.letsencrypt.org/acme/new-reg: bad comm
Oct  5 19:30:22 kernel: /usr/sbin/acme-client: transfer buffer: [{ "_mmyRHollbc": "https://community.letsencrypt.org/t/adding-random-entries-to-the-directory/33417", "key-change": "https://acme-v01.api.letsencrypt.org/acme/key-change", "meta": { "caaIdentities": [ "letsencrypt.org" ], "terms-of-service": "https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf", "website": "https://letsencrypt.org" }, "new-authz": "https://acme-v01.api.letsencrypt.org/acme/new-authz", "new-cert": "https://acme
Oct  5 19:30:23 kernel: /usr/sbin/acme-client: SSL_read return 5: Success
Oct  5 19:30:23 kernel: /usr/sbin/acme-client: https://acme-v01.api.letsencrypt.org/acme/new-authz: bad comm
Oct  5 19:30:23 kernel: /usr/sbin/acme-client: transfer buffer: [{ "_mmyRHollbc": "https://commun