I'm at work, and it's been a long while since I did it, but IIRC the conversion is actually quite simple and painless - except for that idiotic "Arch-Shadow". He was a bit painful in converting (and I've converted every 2e monster in existence... but that one wasn't very much fun, due to the very poorly written monster - and module - overall). *sigh*
If you're just starting the adventure, then you should be a-okay for the first little bit. The PCs won't run across the Arch-Shadow for a while. Just a couple of basic NPCs need a couple of feats, really. (Again, IIRC.)