The first two installation methods use Composer, you can see how to install Composer in the official page.
Clone/download the Wolff repository and run the following command in your Wolff folder:
composer install
This will download all 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
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: composer clear-cache.
You can download the bundles ready to be used, just copy and paste its content in your server root.
The bundles can be downloaded in the Wolff releases page.