Verizon model firmware issues with used phone

[rsrwnab]

I appreciate all of your assistance in advance...

I bought this S4 from a guy on craigslist yesterday and noticed a strange issue with "demo" screen popping up and not going away and not being able to uninstall.

I installed Kies today and it is telling me my device current firmware version is NOT supported and I can't update the firmware.

HERE IS THE INFO ON THE PHONE

Can I root and then upload a standard Firmware to the phone? I can't take this phone back to Verizon since I didn't buy it from them. Everything on the phone works just fine, but i keep getting this to pop up over and over

which is tied to this

and VZW demo in lower right

 

[bhp090808]

This is a display model. Just root and use titanium backup to remove the demo apk or flash a different rom and youll be good