How to delete Simple Panel from the object context?

It seems like this should be an easy question to answer, but in looking around on the web, I could not find an answer.

I was playing around with code. I made a Simple Panel.

Now, when I load a New Blender file, there is the Simple Panel I made. I did not save over the default Blender file. The only way I have found to get rid of it is to delete my current copy of Blender and unzip a fresh one.

Is there a way just to delete that panel and have it stay deleted?

Thanks.