Through the Install Administration page on the Administration Dashboard.

Through the Deploy folder on the server’s File System. This folder allows system administrators and developers to copy or paste a newly developed portlet package (such as a portlet, CAF application, Task application, or deployable package) into a specific directory that is periodically polled by the server. If the server detects new deployable components in this folder, these components are automatically retrieved and installed on the server. You have the option to configure the polling interval that specifies how often the server will poll the Deploy directory to detect any new components.