To move a part of a footer down a line in Excel, first select the footer you want to move. Then, click the "Layout" tab on the ribbon. In the "Page Setup" group, click "Breaks." From the drop-down menu, select "Column." This will insert a column break above the selected footer. Next, select the footer again and click the "Home" tab on the ribbon. In the "Paragraph" group, click the arrow next to "Line Spacing." From the drop-down menu, select "2.0." This will double-space the selected footer, moving it down a line.