Unsubscribe multiple subscriptions for multiple users and products

I am trying to unsubscribe several subscriptions for multiple users and products. When i use method unsubscribe in the object browser, I can only do this one by one. When selecting more than one order, I get the error message "Request procedures: Write permission denied for value approval level". Why is that and what is the best way to unsubscribe multiple subscriptions for multiple users and products?