We were in Eze in April 2010. I don't recall the distance from the parking area to the village, but it was a combination of paved hills and some staircases. But, you're not done once you get to the village, as there are more hills to climb...steep and winding in places, far more gradual in others. At least within the village you can take breaks along the way by ducking into shops, which you are likely to do anyway. As for difficulty... I'm in pretty good shape and found it a little rough at times (mainly as I'm very sensitive to warm temperatures), but my son who has orthopedic issues handled it like a champ. Here is a picture taken a little more than halfway up inside the village. Note the railing on the left, yet that would require walking on some uneven ground.
BTW, the views from the top were WONDERFUL.