We Have Provided images to help you navigate through this process easier.
To edit your server Details navigate to "My Servers", Select the server that you want to edit the details for then click edit.
Once you have selected the server you wish to edit you will be shown this page. It is very similar to when you first created a server.
Here we can edit our server Details such as:
You can find more information on the Discord plugin Here: Adding Discord Plugin
Once you are done editing your server details Click "Save Changes" And your new updates will be in place. Should your server appear as "offline" After the new changes give it some time to re-ping your server.