Here's how to hand off a network license to another user.
First, you have to release your license. Do that EITHER by closing Revit OR by going to the Dock 'License Manager' (gear icon on the bottom right) > 'Manage' under 'Network license' > 'Release Network Licenses'.
After that, the other user has to connect to the network license server to access AGACAD software, if not yet connected.
Here you can find instructions on how to activate the license: Network License Activation (refer to the section 'FOR END USER').
If the user is connected to the license server, the user can simply start using the tool after you release the network license.
You can check who is currently using the license in the license server dashboard using any web browser: http://YourServerNameorIP:2468/web > 'Usage' tab > Revit version.