I want to use 68classifieds with sigma template to build a free advertise website. This means that I will not charge at this point for placing the add. I want to remove the fields related with payment and to keep only "select category", "Select picture", Create property listing", "preview" and "Complete order". There is a way to do this?
Yes - it tells you how to do this in the instructions. You change a few lines in the config file for the module. Then certain steps will not show.
To elaborate on what David has said, this is controlled by the Quick Checkout Module. The instructions for the Quick Checkout Module is the last section in the "instructions.txt" file.