Player How-to: Getting Mods to work on EE, part II
Step OneInstall them as normal.
If you get some time of error message (likely along the lines of it not being to find dialog.tlk) because the mod is using an old version of WeiDU, replace the setup-foo.exe program (or just setup-foo for you OS X/Linux users) with the latest copy of WeiDU appropriate to your platform.
Step TwoGo look at the old directions. Seriously, go look. Now everyone go love on @Wisp for making them all completely unnecessary.
Please note: Some mods still need to be updated for other compatibility issues, but getting an EE-enabled WeiDU is a massive step forward. In the meantime, you can enjoy a slate of G3 mods that have received EE-compatibility updates: a couple of portrait packs, Mur'Neth NPC, or the ubiquitous BG2 Tweak Pack (which, despite its name, runs fine on EE).
When we get around to BGII:EE, we'll have P&P Celestials, G3 Anniversary, Amber, and Auren Aseph waiting (and hopefully more).