It is easy. Why didn't they just use a hex head that could be turned with an allen wrench. You know, a common tool. It might be good to try and find a replacement screw that has a common head.
There is no "screw" - the coils of the spring act like a thread, and the end is bent to the center so you can turn it with a tool. It looks and works just like a helicoil.
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