A few pages back there was a link to a free GIF animator, I used it to make mine
Microsoft GIF animator
First you got to one of
These Boards and click post reply. then on the left you will see a link to upload files, follow the steps and copy the link it gives you at the end. Then go into your profile and click the link to change your Avatar. in that link there is a space to put a URL to a custom avatar. Paste the link from the upload form, save the changes and you have your new Avatar. I hope I helped. If someone could explain it better you can try.