Edit master page without SharePoint Designer

You can download the file from the Page Layouts and Masterpage gallery. After you have obtained it from the website, you can edit it in any text-editor you like (notepad, VS2010, etc.). When you are done you can upload the file again and see your changes.To change the master page from the browser is only available on publishing sites. It is under the Look and Feel heading. If you turn on Publishing Infrastructure under Site Collection Features you will have the option of specifying the master page to use.