Question : Best method to push out Citrix client plug-in to local and remote sites

We have just setup a new Citrix environment 4.5 to replace our old environment.  All of the computers at our remote and local sites have an old version of the client plug-in and we'd like to push out version 11 or 12.  A few questions:

1.  Do we have to uninstall the old client before installing the new one?
2.  What is the best method to push out the new client?  Group Policy?

Answer : Best method to push out Citrix client plug-in to local and remote sites

The new clients will automatically remove/update the older clients but it does require a reboot.  

You can absolutely use Group Policy and it's the least expensive route.  SMS would be the recommended solution if you have it.