Digital content can take up a lot of space on mobile devices. Here I'll show you how to 1) archive a book -- which essentially removes it from your device's storage, and 2) remove a Plus book from your Library completely.
Remove from Device (Archive)
Archiving a book will remove it from your device's memory. To do this, find the downloaded book you want to remove. Press and hold your finger on the book cover until a new screen pops up. Once this screen pops up, tap on Remove from Device:
When you archive a book, it will still show up in your Library, in case you wish to re-download it at a later time. While it appears in your Library, it won't take up any space on your device. Books that are archived will appear with an icon of a cloud:
Remove from Library
Some users like to remove archived books from their Library. As it turns out, only books downloaded with Plus can be completely removed from your Library. Your Library is continuously synced with your purchase history so that your Library always stays current and connected when you purchase content. Due to this, users are not able to remove purchased content from their Library, as the order history needs to stay current. However, if it is a book that you have downloaded with Plus, you will be able to completely remove it from your Library.
Follow the same steps that were used when archiving the book. Press and hold your finger on the cover of the book until the new screen pops up. Then, tap on Remove from Library to completely remove the Plus book from your Library.