The ETA is buried under the MAF. You have to remove it so that you can remove the ETA. Then it's still a little tricky to get it out.
If you look close, you may see a large diameter cable coming off the intake on the back passenger side going along the fender wall where it mates with another connector on the passenger side fender wall. The cable is 3/4" in diameter.
You can't tell until you cut the protective cover to see what condition that the wires are. Pete's web page (he has TWO ETAs in the S600!) has some good pics of the wires and connector.
http://v12uberalles.com/throttle_actuator_rewire.htm
Also shows you how to fix it. . . but don't think that you can
just b/c you think you can solder. But that's another story!