How to get "Fast Ring" express lane for Windows 10 updates

Want to be first in line to get the latest Windows 10 updates, such as the just-released one that offers a first look at Microsoft's new-generation browser called Spartan? Then you'll need to get yourself put into what Microsoft calls the "Fast Ring." Here's how to do it.
When Microsoft updates the preview version of Windows 10, not everyone with Windows 10 installed gets the updates. Only those in the so-called "Fast Ring" get them when they're released. Everyone else has to wait for them. They're in what Microsoft calls the "Slow Ring."
There are pros and cons of being in each ring. If you're in the Fast Ring, you get updates right away, but those updates may be buggy. By the time updates get to the Slow Ring they've been tested more, and so are likely to be more stable. By default, testers are in the Slow Ring.
It's easy to move from the Slow Ring to the Fast Ring, and then back again if you want. For example, you may want to move to the Fast Ring to get a particular update, such as the just-released Build 10049 which has Spartan on it. After that, you may want to move back to the Slow Ring.

To move from the Slow Ring to the Fast Ring, on the Start Menu click Settings, then select Update & Recovery -->Windows Update -->Advanced Options. Scroll down to the section titled "Choose how preview builds are installed" and select "Fast" if you want to move to the Fast Ring. That'll do it. To switch back to the Slow Ring, get to the same location, and instead select "Slow."