How do you adjust the HORIZONTAL on the 2004 and 2005 Bonneville GXPs (and maybe the 04 and 05 SLE'* with that body style)? I know they are different than all other years and models of Bonnevilles. There is aVERTICAL screw and it works fine, but there only seems to be a plastic cap where the HORIZONTAL screw looks like it "should" be. I have searched and searched this forum, and have found many threads about this. Some threads are about people who have had success, mostly by accident and/or breaking stuff. I still have not seen a post about how to accomplish the HORIZONTAL adjustment the CORRECT way. I have also searched the owners manual with no luck. Does anyone know the "proper" way to adjust the horizontal on these headlights? The vertical has a screw that works just fine, but the Horizontal is not the same. I hijacked this photo from another post to help illustrate what I am talking about and the difference from other years and models headlights.

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https://www.gmforum.com/t279101/

Thanks