2001 Opel Corsa Power steering easier to the left

Hi, I have a strange problem in that the car is easier to steer to the left than it is to steer to the right. The difference isnt particularly sever as I did not notic it when I bought it second hand. I am not a mechanic but if the problem is not particularly hard to fix I would like to give it a bash myself. The car is not leaking anything that I am aware of either.

Thanks