According to the firmware guide, the only settings not changed with a Show file are:
The following settings are not stored in Show memories. These settings are local to the Avantis.
• Network settings
• Event logs
• User Profiles
So recalling the default show file and resetting the network configuration (Config/Network – reset) would be the easiest thing to do. I guess you should also look at the user section to make sure nothing changed there, but I would be shocked if someone used different users in a shot term rental situation.