Before you go about editing easy populate to add extra fields, an important decision has to be made. In which table are these extra fields going to be located? In Product table or in a separate table?

Adding new/extra fields to the products table is simpler compare to adding new/extra fields to a separate table.

Adding easy populate new/extra fields to the products table

0. Backup your database and your file.

1. Create new/extra fields in the products table. This can be done directly through phpMyAdmin if you have direct access to your database or through scripting in case you don’t.

2. Edit easy populate import.

3. Edit easy populate export

4. Test to confirm changes

Adding easy populate new/extra fields to a separate table

More on easy populate and easy populate help