The update installer can be downloaded from here (Lync Server 2010) Please see below for installation details.
Lync 2010 Client update can be downloaded from here
Lync 2010 Attendee – Administrator level installation can be download from here
Lync 2010 Attendee – User level installation can be download from here
Description of the updates and the KB articles can be found here
Also note when updating your Lync environment as most updates require updating your CsDatabase as described at the bottom of this support page http://support.microsoft.com/?kbid=2493736