Hi,
This depends on whether you are using the Workstation Thin Client or the Workstation Thick Client.
The Workstation Thin Client (otherwise known as Webstart) is simply opening up a browser and pointing it to the URL of the EM (MOM or standalone).
The Workstation Thick Client is a separate installer from the EM installer.
1. To upgrade the Workstation Thin Client to 64 bit java, simply go to your EM (MOM or standalone) installed directory and modify the Introscope_Enterprise_Manager.lax file. Locate the line that says lax.nl.current.vm=<path to java>
Change that path to point to where your 64 bit java is installed.
NOTE: If you have installed your EM on Windows and you have it starting as a service, then modify the EMService.conf file located in your <EM installed directory>/bin directory and modify EMService.conf. From there locate the line that says wrapper.java.command
and change the path to point to where your 64 bit java is installed.
2. To upgrade the Workstation Thick Client to 64 bit java, go to your <Workstation installed directory> and modify the Introscope_Workstation.lax file. Locate the line that says lax.nl.current.vm and change the path to point it to where your 64 bit java is installed.
Hope this helps.
Regards,
Matt