To install the latest update of TopBraid Composer, please go to our web site http://www.topquadrant.com/downloads/
In order to be notified if a major version exists, and to learn about other new developments, please subscribe to our mailing list http://groups.google.com/group/topbraid-users
There is no need to uninstall your current version when installing a new version. When installing a new version, you should specify a new workspace directory to use. You can then migrate your projects into the new workspace by using Import > Existing Projects into Workspace. This option is available under General import options.