Setting the nameservers (DNS names) is very easy in Namecheap.
1. Log in to Namecheap.com and you should be taken automatically to your dashboard.
2. Click on Manage
3. In the ‘Nameservers’ section, if you are hosting with Namecheap, choose ‘Namecheap Web Hosting DNS’. If you have a different host, choose ‘Custom DNS’.
4. Get the DNS names from whatever hosting company you are using, and put them into the fields as shown below. Most hosts will only have two DNS names. But there are hosting companies that provide 4 names, if you need more than two, just click ‘Add Nameservers’ and add as many as your hosting company provides.
5. Click the little green arrow to save your changes (as shown below).