Thread:FutureKnightX/@comment-2234004-20140823210041/@comment-2234004-20140823211346

You get to the file page, like this one in example

http://buddyfight.wikia.com/wiki/File:Kiri_Judo.png

Then you click on the drop down icon next to "Edit" and select "replace" (or upload new version, not sure what the admins here see). However, Wiki has been known to have a bug where it won't display the new version so if that happens your only option is to delete the old file and then upload the new one.