Download the Thinlinc client:

Configuration:

Make the following four changes after clicking the "Options..." button:

1) Select a reasonable screen size under Screen -> Size of Session.
2) Deselect Screen -> Full screen mode.
3) Deselect Screen -> Full screen mode -> Enable full screen mode over all monitors.
4) Replace "22" with "2222" in the text box under Security -> SSH Port.

^* For more detailed instructions please see Manual Configuration

Be sure to fill in the Server and Username Fields properly:

NOTE: To access different Beamlines or Hosts, simply change the "Server" field in the client.