We will need your old core back. Additional to ordered part price you will need to transfer surcharge to our account. We will rise separate surcharge invoice after you made purchase. We will dispatch ordered part only after surcharge is transferred. You will get back surcharge when we will receive old unit. We will refund surcharge to your account. Customer will need to cover return shipping costs for old unit to our company address: Silmaču street 64, Baldone, LV-2125, Latvia.