Auto trans fluid leaking rapidly from bell housing drain hole
 

Hello, my 89 rx7 vert seems to be losing trans fluid very quickly all of a sudden. It appears to be coming from the drain hole in the bell housing. The fluid is reddish in color and smelled of lightly used oil so I'm fairly certain its ATF. I understand this isn't an uncommon occurrence, and the cause can be a few things. I am not intending to do the repair myself, but my buddys little shop doesn't know exactly where to start. How should I advise them to begin figuring this out?