So you say you're from the South? I'm in OK but had never heard the term so I was off to Google which brought back a link to a book on regional sayings. The book said this usage is confined to the Southeastern US but was uncertain why anybody would attempt to achieve belling a buzzard in reality.
My Dad used to say it a lot when he was speaking of someone who was what he considered totally stupid.
No: There isn’t much reason to do it, but obviously it would be pretty simple, Just go around something dead and capture a buzzard and bell it.