I own a domain: "jjshell.com".

I own another domain: "myrealname.com"

I would like to modify the nameservers of jjshell.com so as to make them point to "myrealname.com". I'm not talking about a redirect. When people type "jjshell.com", the dns will actually be "myrealname.com", where the files and databse are located.

Modifying the nameservers is easy. But what should I do on the "myrealname.com" part to have this setup working properly?