JoshWho, what the Comment plugin do you mean? If it's third party plugin you can contact this plugin developer and ask him about additional implementation.
Concerning the Dislike button, it still lacks the votes. You can vote to increase amount of voices for this suggestions on our uservoice board: https://oxwall.uservoice.com/...oxwall?query=Dislike.
There also was a few discussions on the Forum related to this button:
http://www.oxwall.org/forum/topic/1140,
http://www.oxwall.org/forum/topic/18594.

Just in case, let me remind you on how Like button works:
first click on "like" button allows you to like item, second click on the same button allows you to unlike liked item.

i totally mis understood the question. 

Has nothing to do with 3rd party plugin.

Im talking about Oxwall adding a thumbs down button on the newsfeed. Its been needed for a while. put it right next to the thumbs up button.  That way when some one says their grandma just died no one will click the like button they will click the dislike button. 

Josh, just to clarify, my question was about this:

Quote from JoshWho

The comment plugin already has this feature for a while...

I was wondering what plugin do you mean.
For now, as I said you can vote for Dislike button on our uservoice or develop your own plugin.