I did it just last month and it's very easy! NO need at all to remove the full-length roof rails or buy the half rails. You will want to buy the kit that is used with the half rails and you will be fine.
I have a 2013 with black design package, so it had full-length roof rails. The guys at Baja rack told me over and over it was impossible, but that is NOT right. I actually have been talking with John over at Baja to update their instructions.
I also have some photos I will send to you if needed.
You basically remove ONLY the front of the rail (the foot that goes into the roof). There are a few bolts you loosen and then you can just pull off the front leg. It's VERY easy! The only negative part is that the rail is there, which is fine because it's not noticeable at all. If you really hate it, you can saw it off, but I would just leave it. It's actually nice because you do not need to remove any trim, the hole toward the front is already there and everything is ready to bolt!
If you want to text me for further information, send me a PM.
Also, I see you sent me a PM about my Urban Offroad rack, but it did sell to someone in my local rover club. With that said, I HIGHLY recommend going with the Baja - I can give you more information why if you wish.
I hope this helps!