Automatically connect to new data source in ssrs

Hi,

I have lots of reports created using the version ssrs 2008 and the data source is oracle. All the reports are connected to one DB server. But soon db sever is going to change. So whenever there is a change in the db server I want all the reports to be automatically connected to that new server. So I don't need to individually change the data source of all the reports manually. 

Please help me to find a solution to this problem.

Thanks.