Here is a picture of the airflow meter off of the 1.9 wbx vw engine with the cover pulled off and the multi meter I used to test it.
The cover was secured with silicone caulk and took a while to work off. I used a razor knife to slowly and gently create a seam between the body and the cover
Some people do repair these AFM's by bending the little arm that rides on the metal arc and changes the electric signal. Others clean up the track. When you open up the box you can see how the arm wears a groove in the metal arc. That messes up the connection which cause vanagon syndrome mostly in the 2.1 (sudden loss of power).