Sierra Classic 3500 4WD V8-8.1L (2007)
3. Remove the cooling lines from the clips.
4. Remove the two retaining rings securing the two cooling lines to the transmission.
5. Use a bent tip screwdriver.
6. Pull on the open ends of the retaining ring in order to rotate the retaining ring around the quick connect fitting until the retaining ring is out of the
fitting. Discard the retaining ring.
7. Pull the cooling line straight out from the quick connect fitting.
8. Repeat this procedure to remove all the remaining cooling lines from quick connect fittings.