Yes, we can change the DNS Only If you have purchased your domain name from us.
If you didn't purchase your domain from us, we will not able to change your nameservers since we don't have access to the control where you have registered your domain. Please contact your registrar you bought it from and provide them with the name servers in your welcome email and they should be able to make the changes for you. From most domain registrars, you can do this yourself using the company's control panel.
Please feel free to contact our Technical Department in case you have questions regarding changing the DNS.