The easiest way to install (and uninstall) an add-on is to use the Plug-in Manager.
In the Plug-in Tree, right-click User Root or the first workgroup in the tree, and choose Install .xsiaddon.
If you want to install the add-on in a different workgroup, go to the Workgroup tab and move that workgroup to the top of the list. You can install add-ons only in the first workgroup.
In the Select Add-on File dialog, locate the .xsiaddon file you want to install, and click OK.
You can also install an add-on by dragging an .xsiaddon file to a Softimage viewport. This installs the add-on in the User location or the first workgroup, depending on the value in the DefaultDestination tag of the .xsiaddon.
See Building and Deploying Customizations [SDK Guide] for additional information about other methods of installing add-ons.
