From the way you described the problem, you are more than likely going to need a new Key and Tumbler(the piece the KEY goes into). You will have to remove some of the lower dash plastic trim, the steering wheel, and the trim around the upper steering column where the ignition switch is. There is a wire harness that is part of the switch which will also come out when the switch is pulled. I WOULD HIGHLY SUGGEST YOU UNHOOK THE BATTERY DURING THIS PROCEEDUER. There probably an upper steering column bracket that may need to be removed while pulling these pieces out for replacement. Also, take care when removing the plastic shrouding around the upper column.
HAVE FUN!!!!!!!!! Jake (and take note of all the screws and nuts that hold all this stuff in place)......