I'd imagine that it would be just like any other torque converter removal on any other car. I don't know if there are any extra steps on the V-12 model, but I don't see why there would be.
-Take off the starter
-Take off exhaust system under transmission
-Take off driveshaft
-Disconnect electrical connections and transmission lines from the transmission
-Remove the torque converter bolts from the flywheel
-Remove the transmission mounts and bell housing bolts with jack under transmission
-Lower transmission and pull out the torque converter
If you've heard of any extra steps on the V-12 models, I'd be interested in hearing them just out of curiousity.