1. Install Adobe Digital Editions [ADE] on your other computer
2. Make sure ADE is authorized with same credentials as that of original computer.
3. You can find all your books under "My Digital Editions" folder in "C:\Users\<USERNAME>\Documents\" (for Windows) or "\Documents\" (for Mac)
4.You can transfer your books through email or any harddrive
5. Paste the books under same location on your new computer.
Hope this works !!