Steering wheel removal

[iozero]

I need to remove the steering wheel from my 1980 450SL so that I can get the gauge cluster out. I need to lube the speedometer cable so that the speedometer needle doesn't bounce. I cannot get the allen bolt out of the center of the steering wheel! Short of doing something like drilling it out (not good!) I am at my wits end on how to remove this. Three questions:

1) Does this have reverse threads?
2) Is there a special tool that you can buy,rent,steal, borrow that will facilitate in the removal of the steering wheel
3) Is there another way to get the speedometer cable out to lube it (pull it off at the tranny?) so that I don't have to destroy this bolt.

Would appreciate any help and/or feedback on this issue. Love the tech site. Have spent many a Saturday night doing nothing but learning how to wrench my Mercedes!