Wolff works with composer. In order to use it for the first time you must have Composer installed in your machine.
You can see how to install Composer in the official page.
Once you have downloaded Composer, there are two ways to install Wolff:
Clone or download this repository, after that, open your terminal and move to the folder where the Wolff content is and run the following command:
This will download the rest of the required files and then you will be done :)
The other way to install Wolff is through Packagist: open your terminal, move to the folder where you want Wolff to be installed and run the following command:
composer create-project usbac/wolff wolff "1.*"
This will download the whole project with everything required to run.
If you have any problem during the installation, just remember to clear the Composer cache using: