How to install on mac?

Hi!
I'm a Sims 3 player since like forever
I used to play on Windows, but now I switched to Mac.
Everything is a bit different now (very different!!).

I download one of your Sims 3 games (Supernatural) to patch my game with the Ultimate Fix.
Unfortunately I'm having problems with rar. I installed an app so I can open Rar files, I see all the files in the map but I can't install the game.
I downloaded the base game as an ISO-file, and I don't have any problem.

I don't want to redownload Supernatural again, I want to download all your sims games.
I had them all on my windows pc, but unfortunately everything is gone
So I have to start over again.

Could you help me install your rar filed game? And maybe help convert into Iso?
Just to let you know: I fail at mac for the moment, I need to learn everything. So sorry for all the extra questions I might going to ask

Thanks in advance!
PS: You may talk in Dutch, I posted some questions ages ago in Dutch and that was no problem at that time. But I don't know if you guy's like it that much when I talk Dutch. My english isn't always that good...sorry

Admin edit: Moved to right section.

- ADMIN