If two metallic spheres are given than how can you produce unlike charge on both metallic sphere

Initially both spheres are neutral. We first make physical contact in both spheres then bring a negatively charged rod closer to on sphere ;say sphere 1. Due to electrostatic induction induction sphere 1 gets positive charge and sphere 2 gets negative charge now we can slowly separate both spheres using insulation contact and finally remove negatively charged rod. Hope it helps.