Since Nexus separates its configuration and data storage
from the application, it is easy to upgrade an existing Nexus
installation. To upgrade Nexus, unpack the Nexus archive in the directory
which contains the existing Nexus installation. Once the archive is
unpacked, the new Nexus application directory should be a sibling to your
existing sonatype-work/ directory. If you have
defined a symbolic link for the version of Nexus to use, change that to
point at the new Nexus application directory. When you start the new
instance of Nexus it will read the existing repository configuration from
the sonatype-work/ directory.