Exact steps
The exact steps are :
1: First, make your texture. It can be anything, even a simple grid, like mine. Make sure you're using GIMP, or this won't work.
2: Look at the top of the screen, you'll see a button saying 'Filters...', hover your mouse over that, look for 'Animation', and hover over that. You'll see something saying 'Animate'. Click it.
A window will now pop up.
3: Look in the "Frames" box, and type in how many frames you want. The more frames you have, the longer it will take to process. The more frames there are, the slower the head will turn.
4: Click OK.
5: Wait for the animation to process.
6: Now, hover over 'File...', look for 'Save as...', and click that.
7: A window pops up. Type in the name of the Spinning head, and click 'File extension'. Look for '.gif', and select that.
8: Click save.
9: Log into
http://www.Toribash.com/
10: Click User CP, click 'Avatar', and click 'Use custom avatar'. Upload your newly saved spinny head, and voila!