Removing membership access levels

I am trying to create 4 membership levels If I go to the Access Levels page, I see only three (Supporter, Competitor and Judge) but on the Membership Page ( it lists 8 - the three above, Ambassador (which I want), and it also lists 'Level 2' twice and 'Visitors' twice. I think these were created inadvertently by going through the wizard, but now I dont know how to delete the ones I dont want, add/configure the ones I do and get the same list showing up in all places. Any help?