Switch schools! Lol just kidding! :) you should pray and ASK GOD that question! I guarantee he will answer it Maybe not right away but I PROMISE he will! :) he is like an ask.com who had an answer for EVERY question into world!! Pray it ALWAYS works! :) :) :)))))
First ask yourself what led to these reputations and try to fix them. Make some friends and lead a changed life. Try to do things to win over other peoples trust. Do not argue with others about the rumors, just disregard the questions with a laugh and tell them it was just a stage. To get more details, go to http://www.ehow.com/how_2386258_lose-bad-reputation.html.