The unlocking instructions for Sony Ericsson C902 is,
1 - Switch ON your Sony Ericsson C902 without any SIM Card,
2 - Press the left arrow key/button once,
3 - Press the button * twice,
4 - Press the left arrow key/button once,
5 - The message "Personalize with MNC2" will appear, (or you will have displayed an unlock menu, select the lock you want to unlock)
6 - Enter the Unlock Code.
and
the instructions for Sony Ericsson W890i
1 - Switch ON your Sony Ericsson W890i without any SIM Card,
2 - Press the left arrow key/button once,
3 - Press the button * twice,
4 - Press the left arrow key/button once,
5 - The message "Personalize with MNC2" will appear, (or you will have displayed an unlock menu, select the lock you want to unlock)
6 - Enter the Unlock Code.
Friend i got these unlocking instructions from
Online GSM Unlock.com - Unlock your GSM mobile phone online .It also provides the unlocking service for your both Sony Ericcsson mobiles..It also an reasonable cost.