Break direct external reference.

Short answer: Don't do that. Using external references as sketcher references is inviting disaster. If you want to use an external reference, use Copy Geometry.

However, it can be practical to do it temporarily and then remove the reference, which is probably what you're trying to do here. But the only way to remove it is to go into the sketch and into the References window and delete or replace the reference.

Hi, 

If you want the ability to break feature references on demand, you need to set the following config option:

feat_references_to_backup other_models

This setting tells Creo to backup feature references from other models. In your case, the reference for the sketch would be backed up into the part you are trying to create the hole in. You can control the dependency with the update control options in the geometry backup, just like a copy geometry. The geometry backup feature will be stored inside the feature that is using the external reference.

The reference viewer will not allow you to break references. If you aren't using geometry backups, you will have to break the external reference manually.

Finally, although many people on these forums avoid external references and recommend against them, they really aren't as bad as people make them out to be. If managed well, they can make the design process much more efficient. We design with top-down techniques and tons of external references. Pretty much everything is designed to flex and grow as other things change. The key is to manage the relationships in a logical way and create breakpoints where reference sharing stops. 

Ty