I just packed my books into moving boxes. Over the years I've hoarded so many books on math, physics, computer graphics and guess what.. yeah never read them. Never had the time nor the brain capacity. Oh well, I can guess I can sell them on amazon.
I would make packages with the ones that are said to have some value, and donate the rest. We have local services here that will take used books and send them to where they are more needed or put them in open booths at parks, maybe you have the same.
It's a very good way to quickly go full digital and declutter the house. Some of the technical or scientific thick volumes were a pretty good deal.