Here is a link to a thread on this forum about opening up the Note Pro to replace the battery:
https://www.mobileread.com/forums/sh...d.php?t=339908
It was very easy to do. I would hazard a guess that the Nova devices are very similar. However, having never opened one up, I can't be certain. Nor can I be certain that the third generation of these devices is similar to the first generation. Best of luck.