Updating Connection from BISM to RSDS for existing Powerview report

Hi ,

I am trying to update the connection of existing powerview reports. I have 4 RDLX file each was earlier point to a abc.bism connection . we created reports successfuly and deployed . later requirement came to use RSDS connection instead of BISM. when i am changing the connection and saving the rdlx file, it is not updating the connection . My connection pointing to a tabular model.

Thanks in anticipation :)