how to remove foreign key between 2 tables

Can we make the deletion of the column from the foreign key table optional? Sometimes we need to replace a table that carries the primary key and in that case the the foreign key field(s) which can affect many tables becomes a very difficult exercise to bring those FK fields back to the affected tables. 

I figured out how to accomplish that. First edit the foreign key and remove the relationship. Then remove the connecting line. That way the previous referenced foreign key column will not be deleted from the table. So we implicitly have the option to delete the foreign key column or not. Happy!