The unlocking process depends on your device model. I recommend you check the user manual for your device and to follow the instructions that you can find there. For example, if you're using an Android device, you need to turn it off and to press Power + Volume Up keys. After that, you need to select Wipe data/Factory reset and to follow the on-screen instructions. This process works for all major Android devices models. If you don't have a manual for your device, you will need to contact its manufacturer.