Replacing ignition switch

I have a 94 camry sedan I need to replace the ignition switch on. The car was occasionally not wanting to start, and then the other day, after I started it, it was making an odd noise. I turned the car off, and at that point the starter began trying to start the car again - even with the key completely removed. I have been told that this is the ignition switch. I have gotten the new switch, but am having problems figuring out how to install it. Does the entire dash need to be removed for this? I have removed the bottom portion of the dash on the drivers side and the steering column cover. I have found one screw on the back side of the ignition switch which is fairly hard to reach which appears to be the only screw holding it in. But then there is a little device connected to the switch by a wire that has a button on it that is depressed as you turn the key. This device appears to be screwed in from the top side (where the dash would need to be removed). Anyone have any experience with this?