C = 5/9(F-32)

Could someone help me with figuring this out?
Josh is talking on the phone to his friend Greg who lives in Europe. Greg is used to describing temperatures in °C, while Josh is used to describing temperatures in °F. Greg can use the formula above to quickly convert the temperatures Josh describes to °C.
How can you rewrite the formula so that Josh can quickly convert the temperatures that Greg describes to °F? Justify your solution method.