You can upload an updated version.
When you are uploading your game, or in your case when you edit your game, there is a section where you can setup "statistics" for your game. You setup as many as you wish your game to send there and what type of statistic they are, and then in your game you make sure you have the Kongregate API object, and for each statistic when you are ready to send them (at the end of the game, every 10 seconds, or whatever you want to do) you use the action submit statistic and give it the name you put in the Kongregate side along with whatever the stat is (i.e. total kills, score, etc). That's all there is to it. Screen shots from GSSMPTX:2EB:theubie2013-03-14 02:45:55