First, You need to purchase “Unlock Code by IMEI” from some one else online. Just Google “unlock code for MS769), and choose some vendor who can send you the unlock code by IMEI.
when you have the unlock code in hand, Dial 2945#*769# from your phone to access the unlock menu.
Click the SIM/USIM Lock Menu. and then follow the on screen instruction to unlock your MS769
Wish this helps!