I went through this very problem with my '88 300E just last week. First order a new coded ignition switch and master key. Then you have to get the key to turn to the first position. My mechanic advised me to move the key in and out quickly or push/pull quickly since it's probably stuck in there, and I was able to get mine to turn that way. If you don't feel up to sticking pins into the switch to remove it take it to your mechanic and it will take him 15 minutes to R&R. Lube wont help.
I got my key to the fist position and left it there till the parts came in. I then drove straight to the shop and DON'T turn it off as you may lock the steering again out of habit. Your on borrowed time and if the steering gets locked your into big $$$.
2000 E55 AMG
1970 280 SEL (for sell cheap)
1959 Alfa Romeo Giulietta Spider Veloce