There are a few different ways that you can edit an XML file.
One way is to use a text editor such as Notepad++. With a text editor, you can manually edit the XML file to add, remove, or change elements.
Another way is to use an XML editor. XML editors are designed specifically for editing XML files and can offer features such as syntax highlighting and validation. Some popular XML editors include Oxygen XML Editor and XML Spy.
Finally, you can also use an online XML editor such as XMLGrid.net. Online XML editors can be handy if you need to make a quick change to an XML file and don't have an XML editor installed on your computer.