[h3r0]

4. Click on the Ethernet that got Packets.

IMO: You should say something closer to..
"Click on the interface that you are using to connect to the internet with. (If you're on wifi it could be wlan0 or eth0 for ethernet)"

Ethernet is a specific type of interface, not all interfaces. And all interfaces could technically have packets being sent to and from but steam is only using one of them(The one used to connect to the internet).

Other than that good tutorial, shame I don't use steam, this could be fun to test.