Sometime those small phone accessory shop are also telco agents, can port at their shop. They usually charge some fee though, around rm10. Telco service center usually free but unless telco service center is really near your house better just do at those small shops. Petrol+time might be more than rm10.

Small ustaz shop wont try to persuade you into reg postpaid and shit while telco center staff mostly will, to raise their kpi.