EDIT: (so it's in the first post if others are having this problem)
Since it's not super clear on the wiki page how the commands are supposed to be typed:
changing gender of slot 1 to male would use the command in either of the following ways.
/pokeedit reddarian 1 ge:m
/pokeedit reddarian 1 gem
essentially, there should just be no space between the command argument and the command's argument