Starting in 1969 the ignition lock cylinder was built into the steering column head. There was a spring loaded metal tab built into the cylinder that engaged a slot in the turn signal switch housing.
You need to remove the steering wheel, hub, locking plate, and turn signal cancelling cam. Then remove the three screws holding the turn signal switch in place and pull the turn signal switch partially out of the housing.
You want to use a thin blade screwdriver to reach into the right side of the vertical slot in the turn signal switch housing. There may be a very thin die cast skin covering the slot. Break through the skin and depress the tab on the ignition lock cylinder. It should slide right out.
All ignition lock cylinders from 1969 through early 1979 were retained by the locking tab described above. Later in 1979 the method of retaining the lock cylinder was changed to a bolt that engaged a slot in the lock cylinder. Lock retention was improved preventing the "slam-puller" method of extraction by thieves.
If you need further information on the Camaro standard (non-adjustable) steering column here ara two links.
http://jimshea.corvettefaq.com/wp-content/uploads/2011/02/stdcolumndr_1rev10ja2010.pdf
http://jimshea.corvettefaq.com/wp-content/uploads/2011/02/stdcolumnacardisassemblypage_1.pdf
Jim