Hello,
For delete old data what you no need, best use admin part for Vehicle manager.
Move old vehicle data to new version you may exactly as described in ours backup/recover process:
www.ordasoft.com/News/Vehicle-Manager/up...n-to-20-version.html
Most important there are first do database and files backup.
You may do migration as to free and to Pro version Vehicle Manager
Thanks,
OrdaSoft team