First goto your domains cpanel ,eg.. http://www.lodgelocums.com/cpanel enter your login details
The menu you are looking for is under 'Files' named "File Manager"
Now that you are in the File Manager, your next step is to enter the 'Public_html' by clicking the yellow folder that is toits left
You are now ready to click on which file you wish to edit. To edit click on that file once and a menu will appear to your top right, just click on HTML EDITOR.
AND YOUR READY TO EDIT. Remember to click save when your done.