Write this code into your .htaccess file:
Redirect 301 / http://new-website.com/
Be sure also to declare the moving of the domains from webmaster tools. From Webmaster Tools, click on your old website > click on the “options wheel” > address change.
Another thing. If you don’t want that the users from a certain country to access your website, check this page and write the generated code into .htaccess. Make sure to put the redirection code after the banning code.
This way, nobody from certain countries will know that you are moving your website to a new domain.
If you have questions, leave in the comments.