Once you have your PUK code, enter your PUK code on your mobile as you would a phone number.
The formula to follow is: * * 05 * PUK code * new PIN * new PIN #
So, on your mobile phone's keypad enter:
star, star, 0, 5, star, 'PUK code', star, '1-8 digit number', star, 'repeat 1-8 digit number', hash
Please note: If an incorrect code is entered too many times, the SIM card will be permanently blocked (between 7-10 attempts depending on handset).