HELP, trying to replace ignition switch but key cylinder won't release

I've got a 97 Grand Prix GT 3.8L and I'm trying to replace the ignition switch that has gone bad causing a clicking noise and my lights and heater to malfunction. In trying to get everything appart, I'm up to the part where I have to release the key cylinder but when I press the allen wrench into the hole on the back of the cylinder housing, the key cylinder is not releasing. Should it easily release? Any tips or helpful hints on this or does anyone have a diagram of this part of the process? Please help!