To change the name servers of your domain, proceed as follows:
To do this, log into the Domain Manager under the following url:
Select the desired domain and click on Edit selected domain names.
In the following window you will find the fields to enter the desired name servers.
Note: Before you change the name servers, please check whether important DNS entries (A, MX, CNAME) need to be transferred in order to prevent your website or e-mail from failing!