• Unzip the folder "charts" in your site's packages/ directory.
• Login to your site as an administrator.
• Find the Extend concrete5 -> Add Functionality page in your dashboard.
• Find this package in the list of packages awaiting installation.
• Click the "install" button.

A new block called "Charts" will be created. You will see it in the list of all blocks installed on your website, in the section "Other".