Step1 : First download the Windows Phone Internals 2.3(latest) and install the internals 2.3 on the system.
Step 2: connect your mobile to the system after opening the windows internals , when you connect it displays the operating system and mobile version.
Step 3: select the operation system to download particular version display belows.
Step 4: After download it will display four options on the screen select flash mobile option run.
Step 5: After flashing it show two options select unlock and secure boot unlock v2
Step 6: After unlock boot manually by the pressing power and volume button down repeatly up to reatart you mobile.
Step 7: Enjoy the complete root access to mobile