Problems.

I still have the august 3 version of alpha and don't know how to update it.

 

Left click the desktop icon, choose properties, and select "Open File Location." And scroll down to Update.

 

If you have the alpha, you should also upgrade your forum account. Find the email with the serial number information in it, and there should be a link that will bring you here. It will give you access to the BeamNG.drive forums, and make give you the BeamNG.drive badge on the left under your name.