How to dismantle STL file?

[generatorlabs]

I downloaded a very popular file called "Little Star" in STL format.
I cannot open a STL file in Corel or SheetCam, however I can open it in CamBam.
The file appears unusable in CamBam. (It is one large, flattened, dark blob with no discernible breaks between parts)
I was under the impression the file was going to be a laid out in a sheet like so many other files found here.
If I import the file in Google Sketch I can see it in its 3D form.

So now I imagine this file must be broken apart before it can be used in CamBam or SheetCam right?

What software should be used to achieve this?

I am sorry if this a newb question but I did do a search for "STL" before opening this thread. The search had zero results.

Thanks for the help!