Download the all-grid theme from Github, and add it to your existing Textpattern installation (v4.8 or above).
Upload all-grid to your /themes/
directory on your web server. Then, in the Themes tab of Textpattern, assign your site section(s) to all-grid. Thanks to Textpattern’s Development / Live theme toggle, you can preview how all-grid looks on your site without affecting what the public see.
I enjoy your site very much.
Donald Swain