Yes, though on your own risk.
Go into Content Manager.
Make a copy of the session. That way you have a backup if you screw up.
Open the session for edit.
Open the Config file and change the route KUID it is pointing at to the new route KUID.
Commit.
Note that due to differences between the old and the new route, you might have derailed rollingstock. If that is the case, go back to the old session in the old route, move the rollingstock to a different location, and try the whole process again.
