The main thing to be careful of when working on the inlet manifold is dirt and grit dropping in to the ports. These engines tend to collect it in all the nooks and crannies around that area so its a good idea to vacuum as much as you can out of there (use a short bit of garden hose duct-taped to your hoover tubes) and then if you can, blast it with a bit of compressed air to make sure its all clean.
Then if you squirt a bit of WD40 at the base of each injector it makes it a lot easier to lift the fuel rail out complete with all the injectors. It'll take some persuading but it'll come eventually.
There are some pics on Audiworld of the S8 manifold in bits iirc but I can't find them. Its best to just take the top off and leave the rest in place as. Trying to take the whole thing off is quite complex as you've got all the gubbins around the throttle body to deal with.