how do you replace the shift lock solenoid

In the centre console. You need to unbolt the plastic surround, lift and turn it at the shifter. You will expose the shift mechanism and see an electric switch near the shift lever at the top. Follow the wires attached to it, going under the white plastic, and there is the solenoid. The lockup problem is generally the solenoid but can be the switch or the brake light switch at the brake pedal. You can check this out as well : http://www.aveoforum.com/forum/f94/replacing-btsi-solenoid-fixes-unable-remove-key-ignition-problem-11176/