The 'How' in this question holds two meanings: how as in the Why, or method; and how as in a description of impact. In this essay, I shall attempt to account for both.
How (as in method) did the USA change our formerly British ways? This was done in a 3-step process.
Step one was initiation. In Australia's case, WW2 was what initiated our relationship with America. During the war, we relied on America for protection (like we would have done with Britain if the Singapore disaster hadn't occurred). Australia was an important base for America in the Pacific. This was our first contact with American culture.
Our second step involved strengthening our ties with America. Even after the war, Americans continued their defence role in our regions through the ANZUS and SEATO pacts. We accepted American communication bases and satellite ground stations, and they became one of our major trading partners. American investors and companies (most importantly those in the media business) saw the business opportunities in Australia as radio and film became the most popular sources of entertainment for us due to falling prices (i.e. of the radio) and rising living standards (more spending money).
American soapies, such as Dr Paul and Portia Faces Life, were immensely popular; some (like Blue Hill) ran for several decades. The majority of these soap operas are based on imported US scripts. Only few Australian soapies were successful. When American rock 'n' roll hit Australia in the mid 1950s, most airtime on the radio was devoted to music programs like the Top 40. A hit song was usually American and musical fads such as Bob Dylan, Beach Boys, and Elvis Presley attracted a huge following.
Cinemas were entertainment venues before and after WWII. However, from the 50s, most films shown were made by American or British companies. By 1952, 74 percent of films shown in Australia came from the USA. These American actors and