The directions for the Tardis card aren't awesome if you are a card crafter. There are some much easier ways to do the things she outlines in these directions. You can do it her way and things will work, but if you have some experience, you may wish to use, say, a paper cutter and square punches.
I'm not going to lie to you, the map fold--the interior--was difficult and frustrating. I have no ability to rotate shapes in my head, so I called in the dude, but he fared no better at following those instructions. If you're an old hand at origami, you should be okay. Otherwise try to find a video. (We couldn't.) But it is imperative to make the fold--it has to be bigger on the inside.
I finally just sort of did my best, and as it turns out, that was good enough!
Happy birthday, Alan.