The following is the basic step to modify a user SIP address within Lync 2010.
Modify via Lync Control Panel:
Modify via Lync Management Shell
- Open Lync Management Shell
- Run the following command
Set-CsUser –Identity “Jeff McBride” –SipAddress “sip:Jeff.McBride@domainname.com“
NOTE: The parts in RED are the variables.