Some of the ways to configure server core can be done mainly from PowerShell or from RSAT (Remote Server Administration Tools).
Here I will be using PowerShell to quickly switch from Core to the full GUI:
1. Switch to PowerShell
In the CMD window simply switch to PowerShell by entering powershell and pressing enter:
3. Install full GUI feature
>Install-WindowsFeature server-gui-mgmt-infra, server-gui-shell -restart
After some time, it will restart and then be presented with the login screen. Once you login you will see the full GUI now.