Data transfer from one instance to another

Hi
I have n issue
I am running erpnext v12 in a vm box
my v12 is not getting bench updated and throwing up lots of errors
I downloaded an fresh ova file from the erpnext website
Updated it to v10 > v11 > v12 and is running successfully with all updates taking place with out any errors
Now, i want all data from the previous v12 instance to the new v12
How do i do this
Please help
Regards
Hemanth

There is a related discussion How to restore a database from a backup (bench backup & bench restore)? should help