Marketpress – how to disable user account sign in?

Hello,

Can anyone tell me what code needs edited so that when viewing the shopping cart, I don’t see the Username and Password field for customers to sign in? I just want them to be able to click the “checkout” button and that’s it. I tried deleting the info on the template file but that just gives me fatal errors…

I need to get this out to a customer today.

Thanks.