How do you remove the ignition lock on a 1970 Dodge Challenger?

Keep track of all the screws that you take out.

0) Disconnect the negative terminal of the battery.

1) Remove the steering wheel and disconnect the horn ground wire.

2) Remove the crush can nut.

3) Use a steering wheel puller (pep boys sells one for ~$15) to remove crush can.

4) Remove the screw in the center of the turn signal switch to remove the turns signal lever

5) Remove the three screws from the retainer than holds the turn signal/emergency flasher switch assembly.

6) Feed some wire slack up the steering column to allow the switch assembly to be slipped over the steering column shaft.

7) Remove the ignition switch illumination assembly (now would be a good time to replace that bulb)

8) Remove the screws that hold this part of the steering column housing.

9) It would be best it you had another well or damper puller with the right bolts and spacing. However, as an alternative, you can carefully use two or three screwdrivers to separate this housing. It doesn't need to come completely off. Slide it up the steering shaft as far as the switch assembly harness will allow.

10) Remove the steering column lock plate.

11) At this point you should be able to see the ignition tumbler. With the replacement tumbler in hand, orient the switch so you can see where the retainer clip is located.

12) Using a dental probe or angled metal scribe, you should be able to depress the spring loaded retainer clip which will allow you to remove the ignition tumbler.

Reverse the order to reassemble.