To get a package from the Code Repository, please see instructions given at Retrieving a single Package via CVS
To install a new available package, go to the bottom of the Package Manager page (http://[YOUR_SERVER]//acs-admin/apm/) where there is a link "Install Packages" which redirects to a page with all the available but not yet installed packages. Select the desired packages and follow the steps towards completion.
Please keep in mind that installing a package may cause errors, and that not all packages are 100% mature. Please refer to the package list to learn about each package and its status. Always perform a database backup before installing, uninstalling or modifying packages.
Clicking on either the "Key" or "Name" of a package while viewing all the installed packages on the central Package Manager page will link to a page giving more detailed information about the chosen package. On this page, towards the bottom are options for "Disable/Uninstall". Click on the desired option and follow the presented steps.
At the bottom of the Package Manager menu page, click on the "Create a new package" option which will link you to a new page with a form to fill in the new package details. Please see the Developers -> Tutorial section for details on creating packages.