The same method has been confirmed by @Budrweber but instead of using adb, just flash from your ext sd card.
NOTE: ADB SIDELOAD WILL NOT CAUSE A WIPE, BUT PUSHING THE UPDATE FROM EXTERNAL SD WILL WIPE ALL DATA.
Few users have reported unrooting on NB4 after changing files and downloading the OTA and updating normally.
USB DEBUGGING MUST BE ENABLED, if you are this far there is no need for me to explain how to turn it on. If your phone is unresponsive to your computer even though you have installed, re-install via Kies 3. Turn Kies 3 off before running ADB.
First of all, you are going to need an ADB Sideloader and it can be found here.
Install to directory C:\Mini-SDK
We'll come back to ADB later.
Now you're going to need the update file found here.
Rename the file to update. (DO NOT NAME UPDATE.ZIP, JUST "UPDATE".)
Place "UPDATE" into the same directory as your ADB C:\Mini-SDK
Now lets leave ADB and the Update file alone and start replacing the files on your phone!
You'll need the following files.
system/xbin/dexdump (if deleted you can find the file here or you can copy/paste & replace)
system/csc/feature.xml (If deleted find it here.
Delete the original "feature.xml" and rename "feature.xml.bak" to "feature.xml")
Download the fix.zip from this page.
You do not have to reset permissions, I did not how ever do as you feel and works for you.
Step 1 copy the mobicore-presetup.sh to /system/bin
Step 2 copy all the APK files to /system/app.
Now navigate to system/bin
You should have a "ddexe" file, if it is named "ddexe_real", rename it to 'ddexe".
This should fix all the known errors in the process of adb side loading.
If you continue to get more errors use the file dump located here.
UPDATE: app_process is another recurring error, please grab this file from the dump uploaded from @smokeystack76
Now to the fun and most anticipated part of the day...
Volume + button up, power and home button all at the same time. Release once you see Recovery mode.
Navigate to Update from ADB.
Plug up to USB.
Now, when you start windows cmd prompt, you can either start from the ADB folder is located in by control, shift + right clicking or manual cmd.exe in "run" or "search"
Once command prompt is loaded,
Type in the following command.
"CD /D C:/MINI-SDK"
Then if you are in the right directory and you placed the "update" file accordingly... type...
ADB SIDELOAD UPDATE.ZIP(the file name should not have .zip or you will get a "can not read" message.)
and now you should be on your way to 4.4.2 Kit Kat.