Before starting the activation process make sure you know your License Sever settings (name or IP and port) and Floating License name.
At the beginning you have to start MDT License Manager tool.
Click Add New License.
Select Floating License option.
Provide license server settings.
Press Test Connection button to assure proper connection to license server.
Press Next button. MDT contacts license server to obtain a license.
Activating Regular Licenses
Verifying Active Licenses