How can i change the file extension on about fifty files from html to txt?

i uploaded txt files from another computer to googledocs and now exported them out into this computer, but, for some reason, they all get converted to html





i cant export them as txt





i want to change their file extensions to .txt from .html





how do i change the file extensions of about fifty html files from html to txt with a few clicks instead of manually?|||i had one software for same.


but i lost it while formatting .


google it