Log onto your account (https://id.ie/login).
On your Dashboard page, click on the Domains box (or on top menu, select Domains >> My Domains), .
Find the domain you would like to switch nameservers for and click on the domain options menu (three dots) to the right of it.
From the list of options, click on ‘Manage Nameservers’.
Click on 'Use Custom Nameservers' and fill in the nameservers you would like to change your domain to.
Note: If switching from external/third party name server back to Irish Domains, choose option "Use Default Nameservers"
Once the new nameservers are filled in, click 'Change Nameservers'.