This is wordpress themes basic installations, follow this instructions step by steps to change your free wordpress themes.

1. Access your Web server using an FTP client like file zilla or another web server administration tools.

2. Create a folder for your specific theme under "wp-content/themes" folder within WordPress installation. For example: \wp-content\themes\

3. Copy or upload theme files into the newly created folder.

4. Login to your WordPress administration panel and select Design =>>Themes.

5. In the 'Available Themes' section click on your theme title or screenshot, then click the 'Activate Theme' link to activate it.