Thread:KickMeElmo/@comment-25568099-20141022160317/@comment-1503254-20141022184530

First you find the image. 98% of the time the image will be called spiritname.jpg. In this case it's Hayame_Kaji.jpg since the spirit is called Hayame Kaji.

After you find it [link], scroll down a bit and you'll see these words: About, File History and Metadata. Click File History and below there should be an option called "Upload a new version of this file". Click that and then upload the new file.