Need help with removing Aciera F1 overarm and other unresolved issues.

I completely removed the 2 Allen bolts on the side of the casting that holds the Horizontal overarm .I loosened the Allen bolt indicated by red arrow; this bolt will not come out but only loosens a bit, a feature I assume is part of the design. The overarm is still not budging.:scratchchin:



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Ok now to the universal table swivel support. How do I remove the 2 metal protrusions indicated by the red arrows?



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Got some more questions.
Thanks