How to change Owncloud (& Apache) config from Self-Signed to Let's Encrypt SSL

Current situation
Using Owncloud (with Apache) with a self-signed cert, created following the standard procedure.

Desired situation
Use Owncloud (with Apache) with a Let's Encrypt SSL certificate.

Longer description
I am looking for assistance on how to replace my Apache self-signed SSL cert with a LE cert.

If anyone has a similar setup to me, and has changed Owncloud with Apache from a self-signed SSL cert to a LE cert, I'd appreciate your help.

I've been looking for a procedure to follow to replace a self-signed cert with a LE cert, but can only find a "how to set-up Apache with LE".

I am possibly over complicating things, but I am really reluctant to "just try it" because I use my Owncloud daily for work and can't be without it. :dizzy_face:


Server configuration
Operating system: Debian 7.11
Web server: Apache/2.2.22
Database: mysql Ver 14.14 Distrib 5.5.54, for debian-linux-gnu
PHP version: PHP 5.6.30-1~dotdeb+zts+7.1
ownCloud version (see ownCloud admin page): 9.1.4 (stable)
Updated from an older ownCloud or fresh install: updated from 7.? all the way to current
Special configuration: external storage (attached USB drive), accessible to the Internet


as the SSL/TLS topic is nothing ownCloud specific (oC is just a web application written in PHP and served by your webserver) its strongly advised to jump over to a community like:

where you get support for Lets Encrypt and questions answered concerning the move of your self signed cert to LE.

I'm using owncloud on ubuntu with haproxy sitting in front doing ssl termination. So far works great. If that is something your interested in let me know and I'll post the details.