1. Insert a SIM card not from the current network. IE the phone is not locked to. 2. Turn the phone on 3. If prompted, enter the PIN number of the SIM card. (Assuming one has been setup) 4. The phone should then prompt you for an unlocking code. (Or something very similar) 5. Enter the unlocking code.
(But please check this before ordering!)
At this time we don't currently have any specific information on how to unlock the Microsoft Lumia 435 Dual SIM model , please accept our apologies, we are adding to our help and information sections all the time.