How to define a new service operation from LC Component

I am working with the operation in Process LC workbench. I pick the Repository -1.0 activity it shows only Read Resource Content operation. The Repository service has many other operations like readResource, updateResource etc.. How I define a new operation from the Repository service in order it shows up in the Define Activity popup screen. Thank you for your help

PS: I am using LC Workbench ES 2.5