deleting feature in the group

Hi Today i came across the problem.

I was hadling huge assembly in that "Few of the features are grouped and patterned for example gorup of hole,thread and revolve, its in a group.

This group is pattern, Now i dont want the revolve feature if we delete revelove it is deleting the entire pattren.

Pattern_1
   group_a

     feature_1

     feature_2

     feature_3

   group_a

     feature_1

     feature_2

     feature_3

My question is how to delete the feature inside group of pattern.

Thanks

Chethan