Hello @Robert Adsit,
The process is fairly similar, although you typically dont use a GUI like you may with a fresh one.
You in essence need to go backup/copy the cert from the server its stored on currently, and move it over to reside on your 2013 server.
This article walks through step by step well - https://www.sslsupportdesk.com/how-to-move-ssl-certificate-from-exchange-2013-to-exchange-2013/
It assumes you are moving from one exchange server to another, but the process is the same even if the origination is not an exchange system.
Once the cert is imported, you need to go into the exchange management console and ensure you assign the different services/protocols to it. To do that, you can look at the second half of this article - https://www.digicert.com/util/copy-an-ssl-certificate-to-exchange-2013-server.htm
Hope this helps!