help programing esc
 

I'm trying to program a esc I don't know what it is it's the stock esc from a associated t4 brushless rtr 3300 kv I have the stock esc and motor and I am trying to get reverse to work I have all other throttle positions but can't seem to get reverse programed anyone know the program sequence I bought the truck used and don't have the instructions thanks for the help if anyone can.