Klaus,
Sure here are the steps
1) Download Eclipse 3.1.1 SDK : http://www.eclipse.org/downloads/ (bold link at top should be 3.1.1 quick download)
2) Redownload MyEclipse 4.0.3 from our site
3) Unzip Eclipse to a new dir
4) Install MyEclipse 4.0.3 to a new directory, pointing at your new Eclipse directory as the Eclipse directory
5) Edit the shortcut MyEclipse created on your desktop and add -clean to the beginning of the command line
6) Now run the new MyEclipse installation and point at your old workspace
7) Now try and edit a file and see if brackets work now