Can we change the DS-160? before selecting the appointment dates?

I am applying for my Parents visitor visa. I have mentioned that my parents intended length of stay as 3 months with no particular travel plans. My parents are retired and after going through a couple of blogs it seems that there might be a chance for their visa to be rejected. I have already paid the visa fees and i am yet to take the appointment for biometrics. So is it possible for me to create a new DS-160? or make changes to the existing one and then take the appointment based on this new DS-160?