Hey guys!
Edit: found a way easyer way, to see how to run Mac os 9 on your intel based mac, please see This Thread
Download D2 and D2LoD installer for osX, make sure you have your CDs and serial number. You just need to run the installer application in the dmg and chose what you wish to install
DL linkhttp://ftp.blizzard.com/pub/diablo2/..._Installer.dmg
Have fun!