Username change and event page editing

I want to change my user­name, as mak­ing a new ac­count would delete all my post­ing his­tory, which I value.

I am also the new or­ga­nizer for the Kansas City SSC meetup, and have things to edit on the page (start­ing with the fact that there ap­pears to be a du­pli­cate post­ing of the group).

Who do I con­tact about this?