New Post: How to set the Page top margin to less than 1"

Nevermind i found the answer:

SectionProperties sectionProps = new SectionProperties();
PageMargin pageMargin = new PageMargin() { Top = 1008, Right = (UInt32Value)1008U, Bottom = 1008, Left = (UInt32Value)1008U, Header = (UInt32Value)720U, Footer = (UInt32Value)720U, Gutter = (UInt32Value)0U };
sectionProps.Append(pageMargin);
mainPart.Document.Body.Append(sectionProps);