Ignition switches are a common problem with cars. When an ignition switch dies, the engine will still spin over but will not start. The 12 volt power will never go to the ignition module to power the ignition coils. Ignition switches are similar on all cars and this procedure should work on most. This car is a sunfire and shares the same parts with a cavalier. First you will need to remove the three screws on the underside of the steering column cover.
The top cover will easily come off, and is held on by some clips.
The bottom cover, as shown here, will need the tilt steering stem removed to come off. The stem is metal covered with plastic. To remove the stem it will need to be unscrewed. The best way to do this is with a vice grips behind the cover. Try to get as close to the threads as possible. That way the area that will get marked up wont be seen and will be covered. The stem is very hard to rotate out due to the locktite used on the threads.
After you remove the bottom cover you will see that the switch is located on the bottom left side.
First you will need a special tool to remove the bottom and top screws that attach the ignition switch to the column. The tool which is a female torque star socket, can be purchased at an auto store. When the top and botton screws are removed the ignition switch will pull straight out. Next push in on the clip to remove the wire connectors. There is a clip on both sides one for each connector. Hook up the plugs into the new ignition switch. Set the new switch into place and rotate so that the locater pin lines up into the piece it fits into. You will have to rotate the ignition switch slightly to line it up, then tighten the screws back up. Reassemble the covers that you removed, then tighten the column tilt. If the tilt bar is tight, cover it with a rag then use a pliers to reinstall.