Well for a more detailed example this is what you do you would login into your cPanel.
Now what you'll do is select File manage once inside the file manage you look for that specific file or file you want to CHMOD.
Now click on the file name and folder name and on the far right you should see a few choices that span on from
Delete file/folder
Rename file/folder
Change Permission File/Folder
Your going to click on change permission and then it shoudl lead you to where you would set your permission for the user, group and world. That hsould help you out.