Please make sure that your system meets System Requirements.
You can install and activate this theme just like any WordPress theme.
It is recommended to install this WordPress theme via FTP because usually the maximum file size which is allowed for uploading through the Administration Panel is limited in the server settings. If you get message while trying to upload the theme via Administration Panel: "Are you sure you want to do this? Please try again" or upload process is canceled, it most likely means that theme zip file is larger than maximum upload file size allowed in configuration of your server. Please either increase that limit or upload the theme via FTP.