Nabi 2 Disney return to stock for Dummies?

Pretty much what the title says, I've got a Nabi 2 Disney model that I rooted (at least I think I did) in an attempt to free up more space on the tablet, and would now like to restore to stock so we can get the OTA 3.0 to KitKat update.

While there are a lot of informative posts here some of this stuff is beyond me, even being an IT guy myself (but not a lot of experience with Android, other than what comes with our phones, tablets etc.).

Are there any guides to returning the Nabi 2 to stock from a beginners standpoint, or really good step by step that even someone like me can understand? Here is the information that I have:

Model
NABI2-NV7A
Edition
NABI2-NV7A-US-D
Android Version
4.1.1

TWRP v2.8.5.0 Nabi Jellybean

To make things more interesting (of course) I cannot locate the stock image to recover it with, when I go into recovery in TWRP there is no package to restore, checked the external microSD and there is nothing there either. The original laptop I used to root the Nabi originally has since been wiped so I can't even look for it there.

Can this thing be restored to Disney stock without losing the "Disney" customization? Can TWRP be removed to allow the OTA update to install? We can download the OTA update just fine but when it reboots the Nabi goes right into TWRP.

Any help would be appreciated.