I should first point out that there are other options to unlocking yourself,
1) You can get the unlock code from your provider for free if they are prepared to give it to you. If they are then that is the safest and best option.
2) There are also remote unlocking services - google GSM liberty
3) If you have or know of someone or a store with a smart clip these can be used.
To unlock yourself:
*You need to downgrade your boot loader - this is very risky - no liability is accepted for any problems that may occur*
Ensure your phone is fully charged before starting.
I recommend before beginning you first make a backup of your phone as described in the How To: Use Flashbackup To Backup Your Phone topic in the tutorials section.
This assumes all necessary drivers are already installed.
1) Start in bootloader mode (hold # and * while powering on)
2) Identify your current bootloader (e.g. 8.26 or 7.E0)
3) If you have bootloader 7.D0 already skip to step 6
4) Download and extract http://www.poeticfolly.com/
5) Use RSD to flash the file to your phone
6) Download and extract the Moto Unlocker software from http://www.poeticfolly.com/
7) Start in bootloader mode (hold # and * while powering on)
8 ) Run Moto Unlocker click connect and yes