To apply to the unit change the 169.254.1.1 address to the IP of your Medusa.
Then copy ALL the text starting from 'http:' into a browser that can see the Medusa.
This will automatically apply the key. It should come up with 'Reboot Required' in red text as a reboot is needed for the license key change to be active.
The functionality will depend on the license key, if you are unsure it would be best to speak with your RTM to understand your needs and make sure that you will be legally compliant.