how to load fm8 in logic8

You don't need the vst Lord in order to use FM8 in Logic. There is an AU Plug-In which is located in your Software Instruments Folder->Native Instruments->FM8.
The VST Lord is just a wrapper in case you want to use Plug Ins which only come in the vst format which Logic can't use.
I don't know Antares but I assume it's the same.

VST Lord is a standalone program which can load any vst Plug In. Once loaded into VST you can access the Instrument via Logic's IAC Bus (like an external Midi Instrument) which connects Logic to the VST Lord. Then you can record Midi data into Logic and it will play the instrument in VST Lord. But you will have to get the Audio data back into Logic using either your Audio Interface or apps like Jack Router or Soundflower.

Bitte schön, gern geschehen....