Well - if you do not have the original rom you can go to the Verizon website and jump through all the hoops and eventually you will land where this link takes you...
http://www.pcdphones.com/our-devices/products/56-xv6975
It is the official rom upgrade. you can flash this and be safe to return your phone. Make sure your phone is re-locked when you return it.
may the force be with you... ...always.