Manage Packages
You can also add packages manually, if you installed a minimal distribution such as BasicTeX, or remove them if you want to reclaim additional hard drive space.
You can also get info on packages, and search or view all installed packages. Note that packages which include binary files, such as XeTeX, will only have the relevant architecture installed on your system.
Most commands relevant to package management are found under the Actions menu.
To forcibly remove a package, hold down the option key (alt on some keyboards) while the Action menu is active. Do not do this unless you really know what you are doing!