Moved to Adobe Digital Editions.
I believe this can be done with the Adobe Digital Editions software. Your Kobo ereader, should have come with instructions on how to do this.
Install ADE on the computer.
Don't use the option to run without an AdobeID. If you already have taken that option, use ctrl-shift-D to deauthorize ADE and then restart ADE. It should again ask you if you want to run with an AdobeID. Say 'yes' and give it your Adobe ID details. If you don't have them, I think it gives you a pointer to the website to get an ID.
https://www.adobe.com/uk/account/sign-in.adobedotcom.html?returnURL=http%253A%252F%252Fwww .adobe.com%252F and "don't already have an account" should get you to open an account if ADE doesn't point you in the right direction.
Now when you plug in your kobo, you should be able to authorize it and transfer books.
You may need to use ADE 1.7.2. There are issues with ADE 2.0 and some ereaders; especially reading library books.
Version 1.7.2, it is a little difficult to find, available on Adobe site for Windows and for Mac.
The forum software is sometimes corrupting the link above. There shouldn't be a blank in 'editio ns.html'. The following redirects to the same page: http://tinyurl.com/diged172