Simply using this script
DO
$$DECLARE
p_table regclass;
BEGIN
SET LOCAL search_path='projectman';
FOR p_table IN
SELECT oid FROM pg_class
WHERE relnamespace = 'projectman'::regnamespace
AND relkind = 'r'
LOOP
EXECUTE format('ALTER TABLE %s SET SCHEMA public', p_table);
END LOOP;
END;$$;
projectnman = previous schema
ALTER TABLE %s SET SCHEMA public is a new schema
thank you