lambda tower '86 190e 2.3
 

My lambda tower is loose. How can I remove it and install a new
one. I noticed that the original factory unit is riveted to the body
of the air flow meter. Please advise on a correct installation procedure. Thanks in advance. Chris

The original unit isn't riveted to the throttle body. It's installed with tamper-proof screws, on which the heads break off and leave what you are lookng at.
Normally these are removed with an easy-out-just drill a small hole in the top center of the head and then screw them out with an easy-out.

Gilly