Hello To Everyone, Especially to anyone who has a solution

Okay I have been reading the info about ignitions and how to replace to tumbler. My situation is a little weird and different than it just not turning.
My key will not go in whatsoever, BUT the silver front turns, in fact it will turn all the way around in circles, so I can line it up with that little notch at 2 o'clock. I have a little piece of wire that fits into it and I can feel it engage the little spring thing. I am a little confused though, because What I have read says there are two notches? To use a U shaped wire. I have no idea where the second notch would be. Also without having the key in, even if I push the notches, will I be able to pull the tumbler out? I can push a screwdriver in it or something if it is just a matter of having something to pull on. I already ordered the replacement tumbler and have it in hand. I just need to get the other one out!
My Mercedes is an 1983 380 SEL, if that matters to the specifics.
And I guess once it comes out, I just put the new tumbler in the black barrel and push it back on? Will it just click in or is there something special I have to do?

ANYONE who can give me some heads up will be a HERO

I do NOT want to have to go pay someone hundreds of dollars that I don't have if I can figure this out. I have fixed and rewired many cars and appliances because I hate the thought of paying someone for 10 minutes of work.
HELP!

Many Thanks,
Meshale