To convict on anything the jury will have to believe without a reasonable doubt that Zimmerman did not act in self defense. They will have to determine that he had no reasonable reason to believe he might suffer great bodily harm or death. If the prosecution had any sort of case that might be reasonable, but in this case it isn't even close. The only way I see any reasonable jury deciding that it was anything other than self defense is if they simply lie because they themselves fear great bodily harm or death.