I just went through this process. It is a pain. You need to buy them from lexus, they are different from other sensors that lexus uses on other models. You also need a sensor mounting kit which is roughly $30. I got a good deal on them from some dealership in Texas (Sewell I believe), it was roughly $400 for the set, saved me about $160 from the local dealership. I had the lexus dealer install the pressure sensors and mount the tires (nobody here seemed to know how or if they could be programmed by anybody other than a Lexus dealer), but I have to think that it is a fairly simple process.