Here is what I would do... I would have Verizon reactivate the old Thunderbolt, then go to play store on this thunderbolt and download the verizon cloud app. When you open the app, it will ask what kind of stuff you want it to back up. You can choose to back up just text messages, or more if there is more stuff you'd like to move to the new phone. Then tap at the top right three dots and hit backup now.
After that, just reactivate the Samsung, and open the cloud, top LEFT three lines tap them, hit tools, hit restore content, make sure to include texts on type of content to restore. Done!