If all your files are in the same directory than you can check out this code: <?php $path = "."; if ($handle = opendir($path)) { while (false !== ($file = readdir($handle))) { $extension = end(explode(".", $file)); $name = explode(".", $file); if ($extension == "html") { rename($path."\\".$file, $path."\\".$name[0].'.php'); echo "$file\n"; } } closedir($handle); } ?> PHP:
Of course you can also try: Total Commander's Multi-Rename Tool http://www.ghisler.com/advanced.htm#tutorial_rename
I've also found this program but don't know if this is safe or not. http://www.brothersoft.com/extension-renamer-download-41537.html
Just upload the file into the directory where all these files are that you want to change and then run that script. You may get issues with security. If it throws up an error then you will need to change the permissions on the files and folder.