I used the releasenotes:
http://heanet.dl.sourceforge.net/sourceforge/jboss/jbosside_releasenotes_1.0.3.html
This is a cut from the file :
Eclipse Install/Update Manager
1. Start Eclipse.
2. Select the Install/Update Perspective via Help > Software Updates > Update Manager or Window > Open Perspective > Install/Update
3. Select New > Site Bookmark from the context menu of the Feature Update view. In the dialog fill the name with an unused one and the URL with http://jboss.sourceforge.net/jbosside/updates
4. When you open the newly created node there is a child node called JBoss-IDE 1.0. By opening this child node you get nodes for all versions of JBoss-IDE belonging to this category. Select the version you want to install and some information about this version is shown in the Preview view. If this version or a higher one is not already installed the Previewview offers you an Install button which you have to click if you want to install this version.
Tips:
* If you are behind a proxy you have to go to Window > Preferences > Install/Update, select Enable HTTP Proxy connection and insert values for Host Address and Port.
* You can let Eclipse check if new updates of JBoss-IDE are available by selecting Help > Software Updates > New Updates. Via Window > Preferences > Install/Update you can choose for which changes of versions Eclipse is supposed to look.
* Have a look at the Eclipse documentation to get more information about the Install/Update Manager.
