It is hoard to tell what is going wrong with out specifics.
I need to know the specific errors you are getting. the exact test of the errors.
You dont need to delete the wizard forms, you can edit the existing forms using CSS foerm builder.
In design view, select the first text box, then in the tag inpector, select the Form tag. With the form tag selected, go to Insert -> Web Assist -> CSS Form Builder -> Insert Form. This will import your selected form into the CSS Form builder wizard for editing.