Line Items can't be edit in custom folder

Hi all!

I have a little issue with the line items, i want to customize view in Invoice adding the “item_description” after the “product_name” in any line item.
I find it needs to be change the file in “modules/AOS_Products_Quotes/Line_Items.php”, i did it and it works well!
But now i want to do this with custom folder for make it upgrade safe.
I tried but it doesn’t work, i tried coping also other files from AOS_Products_Quotes, AOS_Line_Item_Groups and AOS_Invoices.
Does anyone know the solution?

Thanks a lot!

Did you do a Quick Repair/Rebuild from the Admin menu after making the changes in the custom folder?

Thanks for reply!
Yes i did it, but no changes.