Replying to Some Help with .jar files. Google Didn't help

I've downloaded a patcher for Minecraft. It's meant to change some elements in the game from SD to HD. Sadly, the patcher was corrupted and when I used it, the program messed up the game.

When I downloaded it a little over two hours ago, it DL'd as a simple .zip file, and as I unzipped it, it was a .jar that right as I clicked it, it ran. Now it only shows a .jar file, but in the form of the folder. Thus I can't run it.
If you're wondering why it changed now, is because my instinctive decision was to delete and redownload everything having to deal with MineCraft.

I'm on the latest Mac OSX update, and Java update by the way.

Thanks.