LLHE winrate question

[NYTyler]

Is it possible to beat the rake in $2/$4 and $3/$6 Limit Hold'em? What is a realistic win rate for these games? I know the rake matters because the limits are so low but I don't know how to break it down mathematically exactly. A lot of people say - pros even - stay away from the low limit tables (I am talking about live play). How high a win rate do you need to win at low limit hold'em?