Making kgpanels art with paint.net or gimp

[Rusken]

So, i've been wanting to learn this for a long time but since i haven't found any good guide for it i kinda gave up a while back.
I have 0 skills and 0 experience with programs like PS, paint.net and gimp so i wonder if someone could give me a quick walkthrough on how to make a custom piece of art?
Lets say i want a simple black 1px circle kgpanel, how do i do this in Gimp or Paint.net?
I have watched this guide but since he is using PS illustrator and PS it didn't help me at all, it just made me even more confused
Thanks!