Books can be installed on a new device any way you prefer. You can synchronise with Kobo, even just via wifi, and it will restore them. You can transfer books to it again using the ADE software, or Calibre, or even any file manager of your liking. Just for the record, I don't like the term "side-load" as it implies doing something in a way different from normal. All these ways are perfectly valid and normal, and none of them are sideways
