How to unlock (SIM) a Sony Ericsson Phone?

Issue

I have made my request from my mobile operator to receive the unlock code my Sony Ericsson phone. I have already receive the code, but how to use it?

Solution

-Remove the SIM card and start the phone

-Press once left arrow key

-Press twice on the star button

-Press once on the left arrow key

-The following message will be displayed "Personalize with MNC2".

-Wait a couple of seconds and select "Network" > "Unlock (Net) 5" > "NCK:"

-Enter the 16digit code provided by your ISP and select OK.

-The following messages will be displayed "Network unlocked" > "Insert SIM" appears.

Thanks to Gouby for this tip.