Changing the PIN code on your LG K3 is quite simple, you just need to know how to do it. First make sure that the SIM card is on your LG K3, then go to the 'Settings' menu of your smartphone, available on the home screen. Then select 'Security' and then 'Configure SIM card lock'. From there, you can change the SIM code of your LG K3. In the case of a configuration with two SIM cards in your LG K3, you can configure two different PIN codes, each corresponding to a specific SIM card.
However, this procedure requires that you know the current SIM code to go to the 'Configuration' menu as described. If you do not know your SIM code, get in touch with someone who knows, since you may be blocking your phone after three attempts. We strongly recommend that you contact an expert to change the PIN code of your LG K3 in this case.