Hello Terry,
This can be done in a number of different ways, depending on your support model.
In all cases, Cisco Customer Support is provided with the device serial number and the correct Site ID it should be assigned to. You can do this via your Cisco Partner, a member of your Cisco Account Team or yourself via My Cisco WorkSpace.
For the self-service option, you can find the link and instructions in the Useful links section of the portal, under Support. Clicking on that link should open a new tab, with instructions for Technical Support on the left, and Customer Support on the right. Follow the instructions in the Customer Support section.
Thanks,
Nathalie