I'm not sure about Pacifist, but for me (in Tiger) double-clicking on a .pkg installs it. I did this last night with a bunch of patches I had saved from Software Update. I believe you can also do this in a Terminal window:
This thread has been closed by the system or the community team.
You may vote for any posts you find helpful, or search the Community for additional answers.
Can't Install .pkg - Using Pacifist - What Utility to look for to install?
Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.