1983 300SD
Last weekend ignition key stopped turning. Key goes in and out, but will not turn without force. (Was doing valve job when it happened)

Took out plastic panel on lock (thanks to PO), did not drop steering wheel or remove instrument cluster.

Inserted key, wiggled with channel locks and inserted 1.5 mm allen wrench in hole when key was at "1".

Now, do I need the anti-theft ring special tool (126-0714) to remove anti theft ring, or is there another way?

Please help me do this without screwing up a really nice car.