How do we get from Valle de Bravo, Mexico to Cuernavaca, Mex. by first class bus?
Second-class bus to Toluca where you MAY find a bus to Cuernavaca (although the only one I can find is a 7.00 am ETN one) - otherwise you have to go back to Mexico City and change (possibly terminals as well). It's not an easy journey. You will get more help once you're in Valle de Bravo - sorry to be of such limited use!
There are not direct buses from Valle de Bravo to Cuernavaca.
i would suggest that you rent a car to drive from Valle de bravo to Cuernavaca or
take a bus to Toluca, then to Mexico city and then to Cuernavaca...From Toluca to Mexico City and Mexico City to Cuernavaca you will find first class buses. There was a direct service between Toluca airport and Cuernavaca but i think they don't have it anymore.