Open .theme file in Mac OS X Snow Leopard I've done a brilliant stupidity...

I have a Jailbroken iPhone and have iFile on that. I wanted to edit a Winterboard theme that I had downloaded, so I fired up iFile's inbuilt Web Server and downloaded the .theme file to my Mac.

I tried opening that but upon right-clicking, I did not get the usual "Show Package Contents" option. After fooling around a bit, I simply clicked on Open with and selected "TextEdit". TextEdit was able to open the file and what showed up was an html file called ".theme" and had real html code with details about the Modification Date and it's location within my iPhone, all in doc format.

Now here's the problem - 
1.  I'm not able to open the theme file to edit. (I've done some editing earlier and know for sure that the Show Package Contents option should have shown up)
2. The .theme file has by default gotten associated with TextEdit and am not able to change it back or remove that association... Help me do that for sure!!! Note- There's no Finder.app that I can associate with that file... Is there a way to do that?
Check with Terminal to see if what the permissions are set to.
Do Command + I to get info on the file, then check the file extension. Also check to see if the default "Open With:" drop down box is set to TextEdit.