GM Service Manual Online
For 1990-2009 cars only
  1. Warm the cylinder using a heat gun.
  2. Hold the shutter door open with a paper clip while forcing air into the cylinder using compressed air and a blow gun attachment.
  3. Inject a small amount of GM P/N 12342241 into the open shutter.
  4. Work the key into the cylinder several times.
  5. Wipe away excess lubrication from the key.