Once you have found the theme that you want for your phpBB forum, download the zipped file. Extract the zipped folder. Log into your site via FTP. If you don't know what that means, see this guide. On the local site side of your FTP software, navigate to the folders you just unzipped. On the remote side of your FTP software, do the following: double click on public_html double click on styles Now right click on the folder/s you ext