How do I edit work items in the Visual Studio 2008 xml editor?

I'm trying to customize some TFS work items via the VS2008 xml editor, but every time I open a work item xml file it jumps to the graphical designer. All that gives me is a "View XML" button that doesn't let you edit the xml directly.

From stackoverflow Luke

• Ah, looks like you have to go to File->Open and click the down arrow next to the Open button to "Open With" the xml editor. If someone wants to copy and paste this, free accepted answer :P

  From Luke

• I don't have TFS but I know in regular VS there is an Open With... option in most items' contextual menu that even let you change the default editor. Very useful when you are tired of the Designer opening instead of the Code file on Windows forms.

  From Coincoin

• As per Coincoin's answer, this feature is also great for setting the default editor for ASPX. If you want to go to the Code Editor most often, then this is a default you'd want to change.

  From Daniel O

• Reading this - I think perhaps you don't realize - that there is no need to edit the XML - in fact it is very difficult to do so. The graphical designer will actually let you change the Work Item type, adding new fields, changing workflow, rules etc.

  The only reason to change the XML is if there's a bug in the Process Editor (the tool that gives the graphic designer). I have done extensive modifications of Work Item types and only had one instance where I had to change the XML.

  From fuzzbone