It is tricky coordinating all of the steps but entertain this thought...
- You build the package and deploy it to a single Citrix server (I'm assuming you are speaking of Citrix clients)
- You then copy this updated PD package directory to all of the production Citrix machines but give it a different name like PD7333.new.
- You schedule a reboot at say midnight, which guarantees everyone is off the machine. (if you want to get more intelligent about it you could send a 10 minute warning notice and bump them off using Citrix commands to clear sessions)
- You rename the PD7333 folder to PD7333.old and rename PD7333.new to PD7333.
All of this can be done with batch files and windows scheduler.
*Now granted this can all be done much more elegantly with more thought, but as suggested by the "wise ones" in the other posts, there are some canned programs that do all of this for you.
You still can't run from CNC = "Late at night", I'm just sayin'!