Interface Arduino with RC Remote to control RC Car

I've searched but I could not find a direct answer to what I'm trying to do. Like the title says I am trying to wire an Arduino to the four buttons on the remote(attached pic) that control movement of the RC car. From what I gathered I need to use relays, but I am confused on how I am suppose to wire them to the remote and then to the Arduino. I have some 5v relays, but from what I read they might not work due to the remote not having enough current to "energize" the coils in the relays, so...

Interface Arduino with RC Remote to control RC Car