sibasish,
Detailed instructions with screenshots are provided bundled in the Eclipse help system.
In Eclipse, click Help > Help Contents and then locate the Database Explorer Quickstart.
We also have guides online here: http://www.myeclipseide.com/images/tutorials/quickstarts/dbexplorer/ They pertain to more recent version of MyEclipse (4.1.x) but it overall process is still the same.
Let us know if you require further assistance,
Best,
Brian.