Move your cursor over some of the letters in the watermark until it turns into a 4-way arrow.Double-click inside the section’s header to open it.
Watermarks have always been stored as part of the header in Word, so: Word 2007 document with a stubborn ‘DRAFT’ watermark that won’t budge, despite going to the section and trying to remove it the usual way ( Page Layout tab > Watermark > Remove Watermark).
Here’s one I solved for a work colleague… Problem