valve stem oil seals

hi again,
can anybody help me out my car blue smokes a lot but runs fine and i'm pretty sure its the valve stem oil seals but can any1 give me any advice on changing them. is it a big job? just put new engine in the car dont want to ave to do it again.
cheers

Hi,blue smoke on take off?=valve stem seals,you can do this with the head in place,but will need a specialist tool clamp to compress valve springs to remove and replace the valve stem seals.
Is it a GTI?if so it can be a bit of a pain to do....but good luck anyhow :)

cheers its an xs are they just the little rubber o rings on top of the valve?