IP-Address and DNS-Server change in Linux / Ubuntu

Use the connection symbol in the taskbar to open Edit Connections...

Ubuntu Edit Connections

Then you choose Wired Connection under Ethernet and click on the Edit... button.

Ubuntu Network Connections

After that you chose Manual from the drop-down menu method. You are now able to add a new IP-address by clicking on the button Add and you can also enter an address for a DNS server.

Editing Wired connection

To save simply click the Save... button and all changes are applied.