Changing your nameservers is as easy as ABC, you can do so by following the steps stated below.
1. Log into your garanntor client account
2. Select Domains.
3. Click the drop-down arrow in front of the domain you want to make changes for
4. Choose Manage Nameservers
5.Use custom nameservers
6. Input the nameservers and click change nameservers
PS : Please be informed that propagation takes up to 24 hours