I would suggest you best option is to go to your local virgin mobile store (a list of locations be found here).
They have a data transfer tool which can do this for you, and is far more effective than trying to do a backup and restore.
Other than the LG bridge, I would plug both phones into USB and manually move the files over, however have had mix success doing this as Whatsapp isnt really built for migrating messages due to it working 'offline' and storing messages locally.
I would also advise to keep aware from other shareware \ free transfer software these cause more issues than they resolve when it comes to data migration.
Please let me know if you have any follow on questions.
Just wanted to follow up to see if you have any further questions, and ask if you can rate the service received today.
Good morning Mike, I just wanted to follow up to see if you need anything else, and ask you rate the service received using the star rating on the page.
So I can close the case I would appreciate it, if you can rate the service received using the star rating on the question page.