How do I clear a default value

Hi

I am trying to work through the Comsol 3D inductor model step by step but am stuck. It downloads with the setup for the frquency domain study. and I can't run the stationary study. I need to define a boundary feed but that boundary is defined as Magnetic Insulation I and is non-applicable for anything else. I can define a Magnetic Insulation II that overrides Magnetic Insulation I but am still stuck with that darn non-applicable boundary 58. It is impossible to delete anyrhing from that initial Magnetic Insulation boundary list.
Thanks for Advice
David