Prepare your environment for theme compilation.

1. Install Node.js via a provided installer: https://nodejs.org/en/download/
2. Update npm from the version packaged with Node: npm install npm@latest -g
3. Install Gulp globally: sudo npm install -g gulp

Prepare your local version of the theme for the first time.

1. Navigate to the root of the theme folder via terminal
2. Install node_modules and local instance of gulp: npm install
3. Make a copy of gulpfile.default.js as gulpfile.js
4. Add your local web address to gulpfile.js
5. Run Gulp via the command line at the theme root: gulp