Some text and a dummy link here in a paragraph.

Get the text from in between the <p></p>

Replace the text within the <p></p>

textContent
"This attribute returns the text content of this node and its descendants. (...)"
taken from
W3C DOM 3 Core textContent attribute:
http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/core.html#Node3-textContent