how to mass update or delete marketing attribute for BP

Hi Team,

Could you please help me, I want to mass update the BP with marketing attribute also i want to mass delete marketing attribute for BP's. I know there is a marketing tool where we have to create a target group for those BP and then we can mass assign or delete the marketing attribute. But when i'm executing that report it is showing "The attribute was deleted for 0 business partners".

I have created the target group using import method from a file.

Pls help, am i doing anything wrong here or is there any other way other than custom report ?

Regards,

Lisha