T4 Camshaft Sensor

[gmotS40T4]

Hi all,

I got the Engine Management Light up on my dashboard yesterday. My local garage read the code for me this morning and said it was the camshaft sensor. I have a couple of questions off of the back of this:

1) How easy is it to replace this myself? (bearing in mind I am not the most technically gifted!)
2) Roughly how much dollar should the sensor be?
3) Can I still drive the car with a faulty camshaft sensor?
4) Is this a common problem with T4's?

Any help would be greatly appreciated.

Thanks,

Gareth