The ownership of the guidestones were given to Elbert County, Georia by the original man commissioned to construct them.
Could a petition with many names and a Gofundme to cover the costs be enough to take it down.....?
That would be an interesting (and awesome) We The People move...
They used to dig mines before machines existed, through solid rock, by first building a fire against the rockface, letiing it get good and hot, then throwing cold water against it.
I assume it's just the inscriptions you want removed.
That would do it, on the cheap.