1. Download JD-Eclipse and JD-GUI - http://java.decompiler.free.fr/ and install.
2. Put a file realignment.jd.ide.eclipse_1.0.2.jar in eclipse/plugins directory.
To use Realignment feature it is necessary to open the menu Preferences/General/Editors/File Associations and to select "*.class" file type and to choose "Realignment for JD Class File Editor" for Associated editors. Another possibility is the batch realignment after processing JD-GUI. To work properly you must to switch on the property "Display line numbers" in Help/Preferences of JD-GUI. To use this feature it is necessary to open the menu Preferences/Java/Decompiler/Batch Realignment and click button "Open dialog".
Existing limitation: the realignment is performed only for the methods. To work properly it is necessary that the property "Display line numbers" in menu "Preferences/Java/Decompiler" was active.