The horn pad or rubber cover with the MB star in the center just pulls right off the front of the steering wheel. Just pull the whole thing off and it will allow you to access the 10mm Allen head...
This all assumes you have no air bags; I don't know if they were available on '82s. Pull at the vinyl pad until it pops off; it will still be connected by screws, but these are easy to remove. make...
What aspect of the steering wheel/system? If you just want to raise or lower the steering wheel, there should be a handle on the left side of the steering column about halfway between the back of the...