Deleting Master data Navigational attribute

I have a navigational attribute ZI_OLDMAT (legacy system material number) that we added to Omaterial. It is referencing Omaterial. I now need to change the object to NOT reference OMaterial. Will I be able to delete the attribute, delete the info object, recreate it and add it back to OMATERIAL and set it to Nav on the cubes without causing queries any problems? It will be named the same.

Any ideas on deleting Nav attr?

Also, Does anyone know how to do a where used to find which queries are using this nav attr?

Thanks, Peggy