What is the value of the 52-volume "Great Books of the Western World" and how do I sell it? Printed in 1952. Entire Collection.

That is a great collection. Prices for that set will vary, depending on condition and how much a person is willing to pay. Check out Amazon.com and you can see how the prices vary. From $235.00 to $995.00.
Amazon.com: great books western world

How to sell that collection? You could try eBay, list on Amazon, try a private book dealer or advertise in media that collectors read.

Excellent answer above!

You could also see if there is an antique and collectible bookstore around where you live. I have sold a number of books to the one around where I live. That might be considered a private book dealer.

You could also try selling them on via any of the free places to advertise for things on the Internet. Most of the better ones are listed on the following link: https://www.askmehelpdesk.com/music/...ng-103010.html