without adb, you have to uninstall the my books app and install again.
You can use the nookMarket app or the nookAppManager app to do the uninstall.
Here are the links:
http://nookappman.googlecode.com/files/NookAppMan.apk
http://nookdevs.googlecode.com/files/nookMarket.apk
Download one of these apk files directly into nook or to your PC and copy it over using usb cable.
You can then install it from the files app. You will have to navigate to the folder where the apk file is and check on it 2 times to launch it.
Use the new app to uninstall my books app. ( long press will uninstall in both).