How much is it to fix the ignition switch? on 1999 Ford Mustang

My Mustang wouldn't turn off. I heard a snap noise when I turned it on and then I couldnt turn it off. I think it's the ignition switch but I have no clue how to fix it or how much it will cost. Also now that I got it turned off I can't turn it back on. How do I turn it on and what's the price to get it fixed?

Asked by for the 1999 Ford Mustang
You can check that price here and locate a shop here