Shine/light flare effect, desaturation, GIMP animation

So we're going from this

to my icon (that I'm posting with)

which won this: Image hosted by Photobucket.com (banner maker sky_dark)

using the GIMP. I'll warn you this right now -
1) it's probably not translatable, I've never heard of a 'Supernova' filter elsewhere.
2) it's very time consuming.
3) it's very sloppy, as a tutorial goes. I didn't write down every step along the way because it was so complex and I really didn't know what I was doing, and I'm almost positive following this tutorial will come up with a different result...

x-posted to gimp_users, icon_tutorial, itutorial (upon approval)

( Motoko's shell, like this LJ cut, is fake, but her memories are very real )