Adding Lower English Leagues

Hi guys it's probably been covered on here before but I'm new to the site. I know how to use the editor and i want to be able to go down to Evostik or Ryman sort of level in England. I've tried doing it myself but i can't seem to do it. I know it's related to adding lower leagues to existing structure. Anyway , any help would be appreciated

Thanks.

http://www.fmscout.com/a-fm2012-england-levels-7-and-8.html

there's a search bar in the top right corner, probably best to use that before posting...