Add text to the Vote Box or add a prompt for new players on how to vote
Add some kind of small text to the vote box or maybe a prompt on how to vote during games. There are way too many players do not know how to kick a disruptive player from the game. Counter-Strike for example has a prompt on screen that says press F1 for yes, F2 for no.
In my anecdotal experience, most votes end with no decision, which usually prompts a second vote with people explaining to others how to vote, which occasionally to a third vote when all of the newer players have caught up to what is going on.