Requirements:

A FreeMC.Host Minecraft Server. Create one here for free

Step 1: Open the panel

This is located at panel.freemc.host - you should be logged in automatically with your account

Step 2: Click on the server

These are shown on the homepage of the panel in a list

Step 3: Click on Configuration on the left

Step 4: Click on Server Name underneath

Step 5: Enter a new server name

Step 6: Click Submit