Hi! Have you rooted yet? That would be your first step.
Here is a thread on rooting your device...
> Android Development and Hacking > Android Software and Hacking General [Developers Only] > [ROOT] $99 Walmart Nextbook 8 (NX008HD8G)
Read the whole thread, there's links for recovery stock rooted ROM etc.
You could ask about other ROMs in that thread perhaps. I'm only seeing ROMs for the SE model, not HD. Not sure if they're compatible.
Good luck! 👍
---------- Post added at 08:43 PM ---------- Previous post was at 08:41 PM ----------
If you need more help, and that thread doesn't help you....you would have to post a thread here and ask for assistance.
> Android Development and Hacking > Android Q&A, Help & Troubleshooting