the couple must apply for their license together to sign the application, under oath, in the presence of the local Registrar or local authority.

There is a 3 day waiting period (72 hours) from when the application is filed, and the license is valid for six months.

Your officiant will confirm the identity of the witnesses and instruct them in properly signing the marriage license.  The officiant will then fill in the remaining required information and have the completed license delivered to the Registrar's office of the municipality where the wedding took place, within a specific time frame. (Usually five days.)
You can contact your local city clerk for specifics such as fee's, hours, appointments.