Open illustrator. Make a new document.
Now go to the retangle tool on your toolbar. Hold down on the little tiny arrow in the bottom right of the tool. The rest of the tools will pop up. Click the star.
Make sure your Fill is black and your stroke is transparent. (if you're new. It's what looks like the foreground/background colors in photoshop.
Hold shift. Make a star. Click the star.
Copy your star. (ctrl+c) Don't paste yet. You're going to need this for later. Also do not move the star or you will mess up things.
Now go to Effect > Stylize > Round Corners.
Turn up. No seriously. Set it to 15.
Click your wonky star. Go to Object > Expand Appearance. Now the wonky shape is set. This isn't your rounded star. The force did not steer you wrong young jedi.
Now if you paid attention in step 3 and copied your star in it's original form you will be able to do this. Hit Ctrl+F. It will paste the original directly over the weird one.
HERES WHERE THE IMPORTANT PART IS. OKAY LOOK AT THIS. Go to window > pathfinder. A boxy box will pop up if you didn't already have it open. Looks like this:
Select both of your stars. (If you don't know how to do this. The very first tool in your toolbar is the arrow filled in with black. Click it. Use it to draw a box around your stuff you want selected. magic.)
Now when you click your stars they won't come apart. This seems like a problem but it's not. We wanted this. Stop panicking.
Right click. Ungroup.
Click the center star shape. Drag it out, select and delete the other stuff. Or you can delete each little section around it while cussing as you keep deleting the center part. But you know. You do you.