Hi Minu,
I've just done this and got it working.
So you've changed the name from page_2 in page_2.php to whatever you want?
Did you save the file as new_name.php?

You now need to go to to /includes/languages/english/html_includes/your_template and upload the new_name.php file to that location.

If you go to zen-cart admin>tools> define pages editor your new page should be available to edit.

Did that work??

Cheers,

Maxy