How do I fix the drive belt wheel alignment on my Reebok i run ?

Hi, my Reebok i-run treadmill is not working due to a problem with the inside drive belt main spindle. I have taken the cover off and see that the wheel attached to the spindle which drives the main running belt is not aligned to the motor. So the small motor belt which connects the 2 parts is at an angle and comes off. I need to move the spindle/wheel to the right about 1cm. Any ideas please ? I have a picture if it helps.
Thanks and best regards