I assume you have an auto. i have an 05 Altise. it depends on how much you trust toyota to provide a lifetime fluid. under severe service on the 4 cyl model, it needs to be changed at 90,000 km. the fluid is probably a lifetime fluid for someone who does only light normal service and plans to dump the car at 150,000km. it is easier to do than an oil change really. get 4 L of T-IV from the dealer. plus a new washer for the ATF plug at the bottom of the tranny pan. I use a Torx T55 socket on the plug, or you can use a 100mm hex male socket to undo. i felt the torx would not strip the bolt as easily as a hex nut. it's a simple case of draining the pan, re-doing the bolt back up (36 ft lbs of torque) and refilling with 3.5L of T-IV. you need to check the level of the fluid after the change. i always check it cold because i can't get a reading when hot. run it in idle and shift through all the gears from P down to L and back up, then pull dipstick, clean, and re-insert. Note the following: a drain and fill only gets about 40% of the fluid out on this U241E auto. if you are pedantic then you can do three or so of these each a week apart, but the gain becomes less each time you do it. I just did it once at 55k and once at 60k and will do it again in 30k intervals from now on. i'm at 82k now and the fluid looks like new. my fluid was brown at 55k! the U241E does not have a filter to replace so taking the pan out would be a lot of effort for not much gain. drive around to heat the fluid up before draining and drain for a couple of hours after that. a lot of people especially the yanks have issues with T-IV but i would stick to it, and it is pretty reasonably priced from Toyota, and purpose made. i think Nulon's synthetic ATF claims it is compatible but it is more expensive, and quite frankly not worth the risk IMHO.