The ThemeSettingsAPI module is only required for Drupal version 5. The features of this module are built into Drupal version 6. If you're using Drupal version 6, you can skip forward to the next section.

You should place all modules in the sites/all/modules folder of your Drupal installation. If you have not installed additional modules yet, this folder may not exist. If this is the case, simply create a subfolder in the sites/all folder called modules.

Download the Tapestry theme distribution and extract the files. The Tapestry theme is distributed in a pkzip or a compressed tar file. Download the appropriate distribution for your platform and extract the contents using a tool such as pkZip, 7-Zip, or Stuffit. Linux users can extract the file using the tar command.

Locate the modules folder of the Tapestry distribution. Within this folder is a subfolder named themesettingsapi. This is the folder that you will copy to your Drupal modules folder.

FTP/Copy/SCP the themesettingsapi folder to the sites/all/modules folder of your Drupal installation.

Enable the module by logging into the administrator account of your Drupal installation, pointing your browser to /yoursite/admin/build/modules, and checking the 'Enabled' checkbox next to the Theme Settings API module. Click the Save Configuration button to save the changes.

For detailed instructions on installing and configuring Drupal modules, check out the Drupal.org handbook page on module installation.