How can i change the space in CarRacing-v0 from box to discrete?

[HoomanAlizadeh]

I wanna train my agent in CarRacing-v0 environment, but instead of box action/observation spaces I want to use discrete spaces so I can train it with DQN algorithm. there is a sayin in openai-gym that says: "Discreet control is reasonable in this environment as well, on/off discretisation is fine."
https://gym.openai.com/envs/CarRacing-v0/

but I don't know how to do it in code or in pragmatic way.