There are two ways to retire Assets, one way if its a computer running a System Client, the other for assets that do not have a System Client installed.
Retiring an Asset is putting it into a Status of retired - this stops the asset from being displayed as an Asset for Tickets to be assigned to it.
Retiring a computer which had a System Client Installed
If the computer is no longer in use and has been removed from the Network you can Log into System Area Manager and remove the system from the Management Tree.
Click on the X next to the system that has been removed off of your network and that has been retired.
Now the system has been removed from the System Area Manager it frees up a license so you can add the replacement system to the Area Manager, it also updates Site Manager and places the system in Retired Status
Retiring Assets that do not have a System Client installed
From the Asset Management Dashboard click the asset you wish to move into a Retired status, this will open up the Asset details.
In this example we are choosing the Printer called NPI4354
From within the Asset General Information screen change the Status from "In-Use" to "Retired"
Press the Apply button to save the changes
You can view the list of retired assets by using the Status filter