I changed my passcode on my lg optimus logic cell phone and now i forgot it and I cant get into my phone how do i fix it

SOURCE: how to unlock straight talk lg optimus logic cell phone puk lock

PUK Code
PUK stands for Personal Unblocking Key. This is a unique eight-digit code specific to your SIM card. This is required when the PIN number to unlock your mobile phone is entered incorrectly 3 times. You are then given 10 attempts to enter your PUK code. If an incorrect PUK code is entered after the 10th attempt, you will block your SIM card permanently and will require a new SIM card from your mobile phone provider.
PUK codes can be obtained through the following ways - The PUK code is in your SIM card documentation Starter Pack. If you do not have this then - Please contact your phone service provider.
Your cell phone service provider can give you the PUK code once you give them your account details and they have confirmed your identity. For details to obtain the PUK code for the SIM card, please click on this link and follow my instructions.
http://www.fixya.com/support/r5705889-puk_code