I have installed Sub Domains, and need to enable a wildcard SSL certificate Mac OS X Yosemite.

In a WordPress MU install that has been around for years, and just moved to a new server after lying dormant for three years, I need to create a wildcard SSL certificate so all the sub-domains are trusted.

The old install was installed as a Sub Domain MU set of sites, (Not sub Folders), and that is the way the convert and import went.

Where do I start on Mac OS X Yosemite 10.10.3?