1. Login to cPanel. i.e (http://www.mydomain.com/cpanel)
2.Under Files, click File Manager.
3.Select Web Root and Show Hidden Files, then click Go.
4. Double click on the publi_html folder to open it.
5. Once opened select the index.php file and right click and select delete.

To upload a new index file:

1. Have your own website file ready on your local PC and rename it to index.html, index.htm or index.php any would do.
2. While the public_html folder is open click Upload from the top toolbar in file manager.
3. Click Browse (some web browsers will have Choose File instead) and select the index file on your local PC.
4. Wait for the successful upload alert and then refresh your website page.