Step 2 allows you to map the fields you wish to import with their corresponding OpenCart fields. Be sure that you match spelling and capitalization exactly as it is in your feed, or the fields will not import.
If you do not wish to import any given field, simply leave it blank. There is no minimum number of fields that must be inputted, so any or all fields can be left blank.
If you wish to deliberately overwrite a field to a null value (for example, you wish to remove the special price of the products), reference a field that is empty in your file. This way, the module will import the empty value as the new special price and thus ‘delete’ the existing special price.