Look straight down right behind the radiator you will see a metal housing. That contains the oil filter element. You change the element.
You can access the element by going underneath the car in the middle right in front there is an access panel with 3 screws. Take that off and make sure you have the correct type of filter wrench to remove the cap. I bought an adjustable one from pepboys which looks like this:
http://buy1.snapon.com/catalog/item.asp?P6...amp;dir=catalog
You can get the original factory lexus one, but why pay $40+ I paid $8.
Good luck.