1. You can do it right on your Kindle by going to the book you no longer want and selecting “remove from device”
When you select the book it will give you a list of options –select “Remove from Device.” The book will go into your Archive. Files in your Archive are not fully stored on your device, but are there to maintain the record of your purchase.
2. You can permanently delete the book through your Kindle account on the computer.
If you want to remove the book permanently you can do that as well. Sign into the Amazon account you have linked with your Kindle and go to “Manage Your Content and Devices.” You should be looking at a list of your purchases. Find the book you want to delete and click the “…” button on the left side of the title.
From the drop down menu, select “delete.” You will be prompted to confirm whether or not you want to delete the file. Click the yellow “Yes, delete permanently” button to remove the file from your library.