No Default Application Sims 2 Install Mac How Do I Use The Sims 2 Package Installer On My Mac?

How do i use the sims 2 package installer on my mac? - no default application sims 2 install mac

Hello, I downloaded modthesims custom content and I did the unpacking of files (Stuffit) and put them in the download folder and so far I have only used the installation package sims 2! I've opened it and say: "Please double-click a custom content file to install the content" Then I double-click on the files they have. Package at the end (black square for the icon ') says that "There is no default application for the document (item name to open), and then gives me the opportunity to select an application or cancel. What should I do?
Thanks