1.3.9 to 1.5.1 build testsite on 1.5.1 then import old database

[enzo-ita]

http://www.zen-cart.com/entry.php?3-...d-of-upgrading

Hi.
I have carefully read all what in the link above from DrByte.
What I would like to do when it comes t the db is exactly the opposite.
In other words I want to start with a fresh install, in a test folder with a new db named test.

1. Install in the test version all the plugin mods and hacking I did in the live site and may be also another template.
2. Import the needed data from the live db to the test db.
3. Test test test and test again.
4. Go in maintenance status with the live site.
5. Import the needed data from the live db to the test db.
6. Back up the live db and files.
7. Delete all the live files
8. Copy all the test site (not the configures files) in the live site.
9. delete all the tables from the live db
10. Import all the tables in the live db from the test db.

It worth to underline that I need to use the italian version because of the VAT and CF fields that are not included neither managed by the original version of zen cart.
Also the italian version includes by default files and tables managing the multilanguage ezpages function but I have learned how to take it back to original version because this makes the italian version incompatible with the templates free or paid present in the market.
Now my question is:
How can i do what in step 2 and 5?
Do I need to do it table by table? If os were cna i find a list of the tables that I need to import?
Is there a tool that is able to import the data without incurring in errors like table already exixsts or data already exists?
I have also read d post telling to use add drop and under Data, choose "Complete Inserts" and "Extended Inserts", but I can not find this in my phpMyadmin version 4.0.10.7. However would this be enough?
Thanks
ciao from Italy
enzo