How to Update Your NameServers
Updating your name servers is a simple process if you have access to your domain registrar’s account (the place where you registered/bought your domain name from, or the place where you have transferred it if you have done a transfer). You should be able to find a place in the account to update the nameservers (usually abbreviated as NS) in the domain account (check your registrar’s faq if you can’t find it). There will usually be two entries that look something like ns1.servername.com and ns2.servername.com, update these to the nameservers that your hosting company gives you (usually two of them is all that is needed) and wait anywhere from 24-48 hours for them to update. See How Long Will it Take My Site’s DNS to Update?