How do you get to the turn signal arm to replace it?

First, if this is an 88 or newer, you will have to disconnect the battery cable to keep the airbag from blowing up in your face. Then, 2-3 small screws on the back of the steering wheel to remove the faceplate of the steering wheel. Disconnect any/all plugs inside the wheel, then with a 19-24mm socket and a ratchet, (at this point you will need to have the wheel locked, or have a friend assist you by holding the steering wheel) Remove the nut, and keeper washer. Now, some steering wheels will come off with a bit of jiggling and pulling, if not, rent a wheel puller from the autoparts store (most places require a fully refundable deposit) Once you have the steering wheel off you can get the switch arms out too. I forgot to tell you to remove the casing for the steering column.