Found the same on my a3 the other day. Dificult job to do or best left to the pro's?
You will be ok im just reluctant to tell people to diy as i actually know a lot of people who cant even change a wheel no joke. But that said as long as you feel confident it wont be hard to do at all. Its just like welly said.Bengal my thoughts exactly!! Looks like a job for the weekend.
As for your running issue on your other thread id get the injector seals done and if its due a service anyway get that done and a scan with vag com to see if theres anything else wrong. A bad injector seal would cause a misfire as that cylinder wont be getting the right amount of fuel could be the cause of the lumpy running.
I cant put a link im not on ebay anymore but i got the name wrong lol its actually mr.injector-uk hope this helps mate.You got a link to that seller mate?