Adapting 4x5 film holders for 4x5 dry plates?

Hey guys,
I've got a bunch of Graphic and Alkon 4x5 holders in rough condition. How would I go about modifying them for 4x5 dry plate? I know I have to remove the septums but I'm just trying to think "How?"

Thanks in advance.
Chris

This website offers a good guide, it's been sitting in my bookmarks waiting for a rainy day and some determination.