Answer:
Temporary? You have two options
If you have a positively charged object, bring it close to the LEFT side of the ball (not touching it!).
If you have a negatively charged object, bring it close to the RIGHT side of the ball (again, not in contact).
Either way, the electron cloud will migrate towards the right side of the of your sphere.
Another option is to have a capacitor large enough to house the sphere inside it, and polarize it by attaching it to a DC source making sure that the negative plate of it is to the right of the sphere.