main problem with this job is the inlet has to come off, and the bolts can be a pain to reach. If its anything liek a MK2 you need an allen bit with a long thin extension to get to a couple of the inlet bolts. once they're off the exhaust nuts are relatively easy to remove, and since its quite a young car you should be able to get them all out without problems. Dont count on it though! I'd buy a set of 8 new studs 'just in case' plus you'll want 8 copper nuts. GSF do the studs & nuts

The trickyest zaust nut is the bottom one on cylinder #3, only tool you can get on it is a 12mm ring spanner. If it rounds off mole grips should get it but access is limited so you'll probably unleash some harsh language.
So in short, before you do anything make sure you can get to all 6 of the inlet manifold bolts. Tap the tool in firmly, and if possible clean out the bolt heads as best you can. A mirror really helps here!
Then once the inlet is off, start with the nut I mentioned above, if that one comes off ok the rest should as well, and even if not you'll have much more room to atack them. Sheared studs are not usually a problem, once the nut is off they should be pretty easy to wind out so long as you have enough of the stud to grip.