How can we integrate google Speech to Text Engine instead of mycroft programatically

I have to use google speech to text and text to speech engine in mycroft-core how can we do this any step-by-step guide or any document is helpful

If you go to, under the settings tab, there is also an advanced tab. In this you can change to which tts and stt engine you would like to use.

Hi, I have selected google tab in as my tts and added api key as provided, But when i run voice service it is giving me following error:-
could not request speech recognition recognition request failed: forbidden
I have done changes to file located at mycroft-core-\mycroft\ where i have changed
like this-
class GoogleSTT(TokenSTT):
def init(self):
super(GoogleSTT, self).init()

def execute(self, audio, language=None):
    self.lang = language or self.lang
    return self.recognizer.recognize_google(audio, "My Api Key", self.lang)

please help me . any step-by-step guide or code can be helpful