Just successfully replaced the glass display on my Note II! I cracked (crushed is probably a better description) the glass display on my Note II a few weeks ago and just worked up the courage to replace the glass myself. I have never done it before and spent a lot of time watching Youtube videos of it being done and getting all of the supplies I needed (glass replacement kit included a pre-cut sticker/tape and some tools for 12 EUR, clear tape, alcohol to clean the glass, glass cleaning cloths, thin plastic and glass knives, hair blow-dryer). It took over an hour, but worked just fine and looks like new (not bad for 12 EUR, a full replacement (Glass, touch and LCD) was around 200 EUR!).
What is annoying is that the quality of the glass display I purchased on Ebay doesn't seem to be the best and in bright light you can see lightly colored streaks toward the bottom of the screen. Also, similar to the problems experienced by Steven, the very bottom of the screen is not very responsive to touch but works fine with the pen... both slightly annoying, but I might keep a watch out for better quality glass and then do another replacement (wish they had Gorilla Glass for Note II, only available for Note I and III for some reason!)... and I can always fork out the 200 for a full replacement some day (maybe prices will sink as new Notes come out)... that goes for anyone doing their own glass replacement, if you screw it up, you will have to replace the whole unit, but it might still be worth a try (if you take the time to do a good job).
Summary: it is possible to replace the glass only, even for an amateur, but with some drawbacks!