Is there anyone-from Australia- or other country-that has landed in Los Angeles and needed to transfer to another international flight.
I will be flying Sydney(Australia) to Vancouver with a change of airlines in LAX
Any advice on transferring

It depends on what airlines you are flying.

Go here & mouse over the terminals:
http://www.lawa.org/lax/laxframe.html

If you need to transfer to a different terminal, you can take bus A. (It is free) It travels around to drop folks off at the different terminals. LAX is not difficult to manuever. It is U shaped. The bus driver can tell you when to get off.

Give yourself enough time to claim your luggage, clear customs, travel to the other terminal (and check in your luggage), AND go through security. Security lines can be longer than what you may be used to Down Under, having have recently returned from a fabulous trip to NZ. All told, the process took 2 hours.

Coming in from Australia, you will either come in to the Bradley Terminal (middle of LAX) or there are a couple of other terminals that have small customs facilities. After getting your luggage, do like the LAX poster said, take the LAX Shuttle A to the other terminal, or it may just be within walking distance depending on the airline.

As far as I know that would all take place in the same international terminal.

No it wouldn't because Air Canada is in Terminal 2 and I believe American also goes to Vancouver and they are in terminal 4. It depends on which airline he's changing to.

Well Peter at least you speak English... We arrived in LAX for the first time, had to change airlines. You have to go outside (to the inside of the U) and pick the RIGHT bus to take you to the correct terminal (ask someone from your arriving airline inside the terminal). I think there are busses A through F? It was very confusing, but not nearly as bad for us as the Spanish teenager on our left and the elderly Chinese couple on our right. We found ourselves helping the foreigners through this very confusing aspect. Bill's suggestion is a good one: write down the bus number and terminal number ahead of time so you don't get mixed up.

What is so confusing? I am from LA and me and another poster told him to take Shuttle Bus A (inter-airport connections). It is so easy. End of story.

Here is from the LAX website.

Inbound transportation unloads on the upper level. Use the 'A' Bus for airlink connections. Frequent, free shuttles are available between each terminal for making airline connections. Use the 'A' Shuttle from under the LAX Shuttle sign.