try this.Ignition Key Will Not Remove From Ignition Lock Cylinder (Reposition Shifter Boot)
Models: 2004-2007 Buick Rainier
2002-2008 Chevrolet TrailBlazer Models
2002-2008 GMC Envoy Models
2003-2004 Oldsmobile Bravada
Some customers may comment that they are unable to remove the ignition key from the ignition cylinder.The shifter boot may be caught/trapped in the shifter assembly mechanism.
Inspect the shifter boot for being caught/trapped in the shifter assembly.
• If the shifter boot is NOT caught/trapped in the shift assembly, refer to Ignition Key Cannot Be Removed from the Ignition Lock Cylinder in SI.
• If the shifter boot IS caught/trapped in the shifter assembly, continue with the next step.
Important:
• DO NOT replace the complete shifter assembly for this condition.
• ONLY replace the shifter boot/handle if damaged by shifter assembly.
Reposition the shifter boot so that it is not caught/trapped in the shifter assembly.
if this does not work please post back and I will help to figure it out.