Just to confirm this for the 09 - I did this on my 2009 legacy 2.5i:
1) Pop off the lower dash cover (two push-screws and 1 push pin in the middle)
2) Look inside - there's a box labeled "DRL Module", I don't remember the exact name. It has a black and a white harness plugged into it.
3) Pull the white harness.
4) Find blue/black wire - pull it out.
5) Done!