Make sure you have Node and NPM installed.
Test to see if you have both installed and working correctly by typing the below commands on the command line.
Both should output a version number:

$ node -v
$ npm -v

After verifying Node is installed correctly, you will globally install Ember CLI:

$ npm install -g ember-cli

After installing Ember CLI, run ember version to show the running Ember CLI version.

$ ember version

Printout will show similar to the following:

ember-cli: 2.x.x
node: 5.x.x
os: XXXXX x64

Now you will have you access to the ember command-line runner.