Profiles are nothing more than SKP files that contain a single face or polyline. If the SKP file was created from Profile Builder it will also contain some additional meta-data about the other attributes of the profile (orientation, layer, material, etc.)
Editing Saved Profile Shapes
Since profiles are stored as SKP files, to edit the shape, just open the SKP file, make the changes using the SketchUp drawing tools and then re-save.
Tip: Be sure that the SKP only has one face or polyline and it is not inside any group or component.
We recommend that your profiles be stored in an organized system of folders on your local computer or network, similar to how you might store your SketchUp Component Library.
Profile folders can be stored at any location as long as you have security permissions to write files to that particular folder.