1 and favorites
Some old books are very collectible. If it is academic and classic books, such books can be collected.
Step 2 read again
Old books can be exchanged with other people's old books.
3. Donation
You can consider donating all the old books to Hope Primary School, or the local library or some colleges and universities.
4, making into handicrafts
There are many tutorials on the internet to turn old books into handicrafts, which can be made into handicrafts by DIY.
Step 5 do second-hand transactions
At present, there are many second-hand trading markets. If old books are relatively new and valuable, you can find some second-hand trading platforms, and after publishing trading information on these platforms, you can trade second-hand books with others.