Usually I have had to follow the article again from scratch as we remove local profiles on log off, and on the re-install it uses a random directory to store the technician client app.
Hope that helps.
I'm not a Citrix expert by any stretch of the imagination, but I'm pretty sure you'll need to go through the entire article like Graham said. To summarize, you log into the Citrix server as the account you've used to present the current Tech Client. Place Citrix into "install" mode. Fire up the Tech Client, and let it go through the motions of the update.
If there are any other functions you do that have the Tech Client talking to common files/applications on the OS, then you should test each of them before coming out of "install" mode. Because we do "on the fly" updates as needed, you need to use this opportunity to make sure each function that you use gets properly updated. For example:
If you use Remote Control, you should also attempt a Take Control evolution to another machine, so that the "local" Guest files within the Citrix session are all updated.
If you've turned off the Email Conversation so that Email Requestor or Email Tech bring up a local mail client window instead of our built-in form, you should attempt one of those evolutions, to ensure that the Tech Client is properly talking to the local mail client.
In your particular case (from 11.2 to 11.4 of Track-It!), there are no Crystal files to update; but in some other Track-It! updates there may be. So, it's not a bad idea to test out the ability to print a report just to make sure Crystal is all updated and functional within the session.
Once you verify that the Tech Client and all of the parts it touches are properly updated, then you drop out of "install" mode, and present out the new Tech Client.