A4 ignition coil
 

Hi,
I have a 2002 A4 2.0 petrol. The car is very chuggy and the engine management light flashes when i'm driving. it happened about a month ago and i brought it to a garage and i was told the ignition coil was broken. The mechanic replaced it and it cost me €120, which sounds very expensive for what only took him a few minutes. Is changing a coil something i could do myself? If so, where could i buy these coils? Do they have to be Audi specific coils?

Thanks.