I got 98 S420.
I was able to loose the gas paddel by remove and change the spring in gas regulator(located under the hood close to driver windshield). there are two spring, I remove one and loose the other one.

However, I was yet figure out how to make the brake loose. I really like to make the brake feel as light as possible. anyone got any idea?

one of the biggest complain from me and many others I know is that both the brake and gas are way too hard. believe me or not, my wife, after spending one year behine the s420, her right leg is fatter than the left one!