Those docs are kind of outdated.
You can do what you want from the command line (I think), but now the commands are different, and there's no GUI, except for Android Studio.
I don't have the computer at hand, but if you are using a Mac, something like this should run the emulator:
$ANDROID_HOME/tools/bin/emulator -avd [device name]
There should be a similar command to do what you want, check the Android official documentation.
As a side note, the installation script used to work flawlessly until TNS 2.5, but after 3.0 it requires some extra work... But I think it has something to do with changes in the Android SDK.
Using Android Studio is a good idea for now, but I ended with the SDK installed in two separate places, and having to modify various system path variables (exporting in .bash_profile, etc.)