This is how you get into Oxenfurt without a pass, it's extremely simple and requires no effort at all.
Get in to Oxenfurt without a Pass
The Boat: First go find a boat off the coast around the Oxenfurt bridge.
The Port: Make sure you take the boat to the port and dock there.
Screw Around: Congratulations, you made it and everybody is cheering for you. ♥ of the guards a little bit, they don't care. (They actually do).
Just to Make Sure: To make sure your new found victory is a new found victory go to the Oxenfurt bridge and talk to the guards. They will think you have the pass... maybe.