How to Update the SSL Certificate when using Plesk & RHEL

If your Apache-based website SSL certificate expired and you are using Plesk to manage your domains, here is how you update the certificate:

1.  Follow the instructions on how to generate a new key for apacheSSL.  Here's an example from GeoTrust's website:  https://knowledge.geotrust.com/support/knowledge-base/index?page=content&id=AR876

2.  Find the location of your certificate file.

$ cd /var/www/vhosts/yourdomain.com/conf/
$ vi httpd.include

Search for this section in your httpd.include file:
        SSLEngine on
        SSLVerifyClient none
        SSLCertificateFile /usr/local/psa/var/certificates/cert-BHkRhb

In the above example, cert-BHkRhb is the file containing your certificate.

3.   Replace the contents of your certificate file with the new key generated in Step 1.  The file contains the BEGIN RSA PRIVATE KEY and BEGIN CERTIFICATE sections.  It's probably a good idea to backup the certificate file before replacing its contents -- otherwise you might have problems restarting Apache.

4.  Restart Apache HTTP server using the Plesk Admin interface or
$ /etc/init.d/service httpd restart

That's it.