Model R6400v2, looking how to change the router name and it's password

> Model R6400v2, looking how to change the router name and [its]
> password

   "looking" where?  Which "router name" and "password"?  Here's a
radical concept which works for some people:

      https://en.wikipedia.org/wiki/RTFM

   Visit http://netgear.com/support , put in your model number, and look
for Documentation.  Get the User Manual (at least).  Read.  Look for
"Types of Logins" and "Specify Basic WiFi Settings".  Further reading
might not hurt, either.