I heard that lubing it up and applying vibration to it (e.g. from a
sanding machine) may help to get it to turn one more time.

You have to turn the key a little to be able to remove the cylinder and
replace it. If you can't turn it it has to be drilled out.

Ximinez

You are right on the cost of drilling that out and replacing it. Let the
dealer do it so they can match your original key.

In the meantime, you can try to get it to on position to save money and time
and tow. Squirt some graphite lock lubricant in the hole... Then use your
key and try to wiggle it in all direction and angle or circular motion while
you are holding the steering wheel in the middle of the tension... if
steering wheel is against the stop, it will be extremely difficult to get
the ignition key switch loose.

Once you get it in on position, go direct to dealer to see if they can do a
quick swap with a temp one...But never turn the key to off!... leave key in
acc to avoid draining the battery.

Check this out as well:

http://dieselgiant.com/repairignitionlock.htm

Ximinez