Well, to do this you need to have a digital certificate installed on your server. This is something you need to ask about on another forum. If you have a web host they should know exactly what to do, however https will probably fail like you mentioned until you have a specific location installed that can accept the https protocol trhough a digital cert.
Hope that helps. If you have your own server you have some work ahead of you, I've never done that before myself.
Sam Fullman
Compass Point Media