Update name servers

Solicito a vossa ajuda para resolver este problema, sou novo nisto:’ Your domain is not yet pointing to our servers, so services such as FTP, Website Builder or File Manager may not work. You need to update nameservers to ns01.000webhost.com, ns02.000webhost.com for your domain. This warning will be removed once your domain will start resolving to our servers (24-48 hours after the nameserver update). How to update the nameservers?’