How do you change your name on Pokemon Mystery Dungeon Explorers of Time and darkness?

it's very complicated. you must first finish the orinal game ( with grovyle and Dialga) then you need to complete the graduation test from the guild then your allowed to change the leader. chemico (or something like that) take's up the desk on the 1st floor of the guild and the funny little signpost at the cross road's call's her to you but in both place's you can move around and change your team.