I did three of them just to make sure the procedure was repeatable. All three came out easily with this process: 1. Used a small-bladed screwdriver to move the CPA clip up (not off) as shown in the photo below. I inserted the blade in the groove at the bottom of the clip and then gently pushed up. Probably a pick is the better tool? If I pushed up firmly then the clip came all the way off undamaged, but perhaps lost because it could have landed anywhere. I was lucky to find it. For the rest of the clips I kept my other hand over it so it didn't fly off anywhere. 2. Pressed the top of the CPA clip in. The top of the CPA clip is actually marked "PRESS" as shown in the photo below of the cleaned up part. 3. While pressing the top of the CPA clip in, pull up gently on the injector connector assembly. 4. Off! CPA = "Connector Position Assurance" as referred to in the GM service manual. With hindsight, the procedure in the service manual is consistent with what I did; I was thrown off by the two diagrams not matching what I was seeing. Even now that I know better, I struggle to see how those diagrams are applicable to my installation.