Some tools:

• refer: http://jd.benow.ca/
• install: http://jd.benow.ca/jd-eclipse/update

There is one more important step pending:

1. Step1: In your eclipse application go to Windows > Preferences
2. Step2: General > Editors > File Associations
3. Step3: Click Add for Associated Editors
   • Select *.class and add Class File Editor and make it default.
   • Select *.class without source and add Class File Editor and make it default.

Now you can open your code and you should be able to decompile any of your jar files by either Ctrl + Clicking on the code base or via your Package Explorer.