Please share the model number of your device so that we can provide suitable manual to you but as you below given method is for unlocking LG metro PC's phone. I hope this would work for you, if not then please share model number:
The MetroPCS network has almost entirely moved to GSM and LTE. These two technologies rely on SIM cards and can easily be unlocked using these methods. In rare cases, your phone will not have an SIM card. This means it uses CDMA technology, and you will have to contact your new carrier to unlock it.