Dopey, I am doing mine this week (Driver's side what seems to be more common). I bought a new manifold online, about $60 - note I went with the Crown setup what has a thicker casting than the crappy stock manifold, and will still bolt up. link for one I bought on ebay:
http://www.ebay.com/itm/261957348392
Removing the shield takes a few bolts and you should be able to see your stock manifold cracks right away. I think it should be a quick job and straightforward as long as your bolts are not rusted up. Use some PB blaster. One tip that has worked in my case on other cars for removing the manifolds is to run the engine for a few minutes so the metal will expand a bit making it easier to remove the bolts, flanges etc.
There are plenty of write-ups online, I am following this one:
link
good luck!
Gui