Do you mean the roof racks or the crossmember? If the crossmember there is a thread specifically for that with pictures. Once you remove the crossmember, the roof rack is held on by two bolts at the ends. However before removing, you need to buy a patch to cover the bolt holes. There is also a thread on this but I dont know the subject off hand. You need to search. But its doable.
Be careful removing the bolts that hold the roof rails on. There are two at each end, and the nuts are mounted on a flat plate inside the roof, and project up through two holes. Those plates are held in place by a spring clip also hidden inside the roof. I cursed and swore through what should have been a simple half hour job to remove both rails when one of those spring clips popped off while undoing the bolts, allowing the retained nuts to drop down inside the roof. I was eventually able to pry down the headliner above the drivers door and force my hand inside to find the parts, pushing the nuts back up and capturing them with a bolt - never did get the spring clip back on, there's not much room to work, and there's an airbag up there! Taking off the grab handle didn't help either - just a tip - you don't need to disassemble the grab handle to take it off! To add insult to injury, the covers that my dealer sold me were too short and too wide, must have been for an earlier model, but he swears he used my VIN number when looking them up. Roof rail reinstalled, parts returned for full refund, much wiser RX owner who's now completely happy to leave those ugly rails alone.
Sewell actually sells the kit you need to remove the roof rack and cover up the holes. There is a different bracket that gets used to hold the cover plates as well as shorter bolts, you do not want to use the ones that came with the roof rack. I took mine off the day I bought it and had no problems. Sold the whole thing on Craig's List as I did not want to store it. I like the look better and it is easier to clean. When I take it in for service other customers ask about my RX not having the rack. Too funny.
PS The hardest part for me was removing the plastic covers on the ends of the rails.
I'm going to remove mine since my RX is Cashmere beige and they look silly painted silver with a beige car, plus we will never use them and its a pain to dry around them when washing the car. Does anyone have handy the Club Lexus discount code for Sewell Lexus? They list them for $91.00 on their site.
Cruiter, I have to say that I like the look of the RX without the roof rack. What does the roof look like where the rack was removed. Our RX is silver and the rails are silver as well, so it really does not look bad. I doubt that the boss would even consider allowing me to take the rack off.