Indesign script to add/change text in a paragraph

There's a particular paragraph in my document and I want to replace its content completely with something else programatically. Is there any function to do this? I need something like this:

app.activeDocument.stories[7].paragraphs[0]. = "blah blah blah";

where <function> is the function that would allow you to replace the content of the paragraph in question to "blah blah blah." I bet this is possible but am not aware of the functions available.