I want to add few options with already existing web part and customize it more using sharepoint designer.I do not get the needed options through browser customizations.Is it possible?.. How can i open a particular web part in SharePoint designer?
It depends on the web part. If it is an XSLT web part of some sort, such as DataView, then yes. Otherwise, you need to change it using Visual Studio (if you have the sources of course).