Make the contextual links button visible by hovering your mouse over that area in the page. In most themes, this button looks like a pencil and is placed in the upper right corner of the page area (upper left for right-to-left languages), and hovering will also temporarily outline the affected area. Alternatively, click the contextual links toggle button on the right end of the toolbar (left end for right-to-left languages), which will make all contextual link buttons on the page visible until it is clicked again.