In 5.x, its all about themes. most things are displayed with template tags. you move, add or remove template tags to change, add or remove display elements… so to remove the stats you edit your sp theme and remove the template tags that display them… In this case, in your sp theme, template file spFoot.php (since it shows up at bottom of every page)… edit the template file and remove the display of the stats stuff – it will be quite obvious…
oh, and we strongly urge you not to edit one of our themes or you will lose your changes on upgrade… simply make your own theme from one of ours…
see: http://codex.simple-press.com/codex/themes/theme-basics/creating-a-theme/