Mod Basics First things first, grab this file: http://www.killeverything.com/files/ToEExtract.rar take the EXE out of it, this will extract the dat files. Drag dat onto exe worked for me, YMMV. ToEE1.dat has pictures. ToEE2.dat has Audio. ToEE3.dat has text stuff. modules\ToEE.dat has miscellaneous stuff. If you extract ToEE3.dat for example, it will auto-extract to \ToEE3\ - the modified data will need to be moved into the \data directory to get it to load in-game. For example, you would move G:\Temple of Elemental Evil\ToEE3\mes\description.mes to G:\Temple of Elemental Evil\data\mes\description.mes Stuff from the module dat file should end up in G:\Temple of Elemental Evil\modules\ToEE\mes\gamedesc.mes Anything in a directory called (null) go straight in the \data\ directory itself. After you've got stuff moved around right, browse the files a bit and you should be in a good position to help in the needle hunting
Also please note that dragging dat files onto the exe should work, but if it doesn't you'll need to use a dos prompt. and E has more info
It's worth mentioning (sure some of you noticed already) but tig.dat seems to have some UI components in it, including a bitmap containing every letter in their font.