Get your 2011 year-end balances, and hit the RESET ACCOUNTING button.
I did this at the end of 2009, and again at the end of 2010. Just make a backup of everything before hitting the RESET button. I restructured my COA at the beginning of 2010, and corrected my mistakes at the beginning of 2011.
You will be looking at one week's worth of work, instead of one year.
