I have an 07 LS460 that I bought with 116,000 miles. I wanted to change the fluid as well but the dealer said it was a 'lifetime' fluid. I brought it to the best transmission shop that I know personally. They said that the fluid is more of a hydraulic type fluid and should never be replaced. They have had customers that have demanded the fluid change and two of them had transmission failure within 1,000 miles. Since then they refuse the service. My advise is don't mess with it. FYI