Altiris 7.1 , how to release License from decommission Managed PC?

Hi All,

I have a All-in-One Altiris Notification Server 7.1 (Virtual Machine) for PC inventory & software deployment with MSSQL database 2008 R2.

Recently, I found some of our New PC haven't installed the "Altiris Software Update Agent".

After checked, our agent license of "Altiris Software Update Agent" is reached the limit (1499/1500).

In fact, many of PC that we installed Agent before are already decommission and disconnected from Network already.

What should I do to release those license on these decommision PC? Thanks.