Need help ESP problem. 3.0 V6

[le3boiluke]

Hi, im new to this forum. I recently sold a car and the guy wanted me to take his old car 4 part ex which is a 607 3.0 V6. Everything is fine except the ESP warning comes up. I am a car mechanic and work in a garage so we have a couple of scanners, the car comes out with steering angle sensor and is permanent it wont clear. Have done some searchs on here and people have said about resetting the system is there a pacific way you do this? And also i have read the steering angle sensor is behind the steering wheel, do you have to remove the steering wheel or can you get to it by removing the cowling around the back of the steering wheel? Any help would be great. Thanks