I don't think you can. It's part of Verizon's bloatware package. I'd be interested if anyone can get rid of it without root.
^^^what he said.
I've been researching this for a while tonight. Truly, there is no way to disable but, here is a thread that people were discussing disabling it. A Verizon Wireless employee chimed in and confirmed it can not be fully disabled or removed.
However, I did find it interesting that Sync Service can be disabled. I did disable it. So far no ill effects. That should keep it from contacting Verizon and feeding them my information.
I didn't activate the service when I set up the phone, so there is no way they are being fed any information from me. At least about my contacts, anyway. All of my contacts are Google contacts.
Of course Verizon knows exactly who I'm calling and where my phone is whenever it's on...
Separate names with a comma.