I have been told to change my name server to something else so that I can use my domain on another site. How do I go about doing this on dreamhost.

if you have registered your domain through DH, then just log into the Panel > Domains >Registration and modify the name servers.

If you have registerd the domain name else where, then you will need to log into your account with that comany and make the changes there.

Sorry to see you leave.