Installing BIDS(Buisness Intelligence Development Studio) in Sql2008 r2

Hello Friends,

                     I am having Sql2008 r2  installed on my computer, the Buisness Intelliegnce Development Studio is not installed in it,now i want to add the BIDS feature to SqlServer, please  any can tell how to do this, i googled alot but i did not find any proper solution.

Thanks and Regards,

Harnek