You can download it here. eaef14432ff5.signed-mantaray-JDQ39-from-JOP40D.eaef1443.zip
You should be able to sideload it with the command; adb sideload eaef14432ff5.signed-mantaray-JDQ39-from-JOP40D.eaef1443.zip
I tried this morning and had no luck doing it that way. I had to go to work and didn't have much time to play around with it.
How to Set Up ADB / Fastboot with Android SDK for Any Andorid Device
(Thanks clo821 for the link)
How to install JDQ39 for Rooted and Non-Rooted
(Thanks Chrizzl3 for the link)