How do I disable some of the required fields in IonCannon’s Express Checkout?

[I am Oleg]

Hello Prestashop lovers!

I am very sorry for creating exactly the same topic. But there were no any answers in that topic and that is old. Punish me if needed.

The link is: http://www.prestashop.com/forums/viewthread/67512/third_party_modules/how_do_i_disable_some_of_the_required_fields_in_express_checkout/

Question:
How to disable some of the required fields in IonCannon’s Express Checkout?

I digged express-order.php up. But if I disable something there, I get “Requested file not found” error when I click “next” on the addresses page (there where you can write a comment to an order).

What to do there to disable the fields?
Thank you for any attention!