Basic steps to get you going should you choose to DIY.
Swear Factor: Extremely high
Notes: I would advise to NOT do this yourself unless you have small hands and A LOT of patience. Working with the 2GR in the Aurion engine bay is not the most pleasant experience.
Okay, so if you're not aware, the 2GR-FE in the Aurion (and other cars for that matter) had previously had a design fault which can lead to oil loss. The Aurion's affected are generally those that were built prior to 2009. There is quite a lot of discussion over on the Toyota Nation thread "ATTN: All 2GR-FE V6 OWNERS!!! BEWARE!!!", as well as over here in "Alert to V-6 owners - possible oil leak!".
I'll let you do the reading further into those topics as this thread is here just for reference. It has been said that the leak mainly occurs anywhere between 45k to 65k miles (72k to 104k kms). Now this part replacement would be covered under warranty, but I believe that they will only change it once the leak occurs. This in my opinion is too risky as even with a small leak, you can lose quite a bit of your oil really fast. You can see just how fast the oil comes out of a pinhole leak from this video:
If you wanted to be safe like I am, you can purchase the replacement pipe plus gaskets for around $45 and either change this yourself, or get Toyota or another mechanic to change it for you at cost.
The part numbers are:
Pipe Oil No. 2 - 15772-31030
Gasket - 90430-16012
Gasket - 90430-16016
Gasket - 90430-16017
So with all that said, yesterday I purchased these parts, and today I fitted them.
The general instruction to replace the pipe itself can be seen in this PDF:
However, getting to it all in the first place is not the easiest thing to do while the engine is still in the car. The following is just a helper guide to give you the idea. It requires that you know how to fill in the gaps in terms of basic automotive work. If you can't figure this out, don't attempt this procedure. It's not for beginners.
So basically, you jack your car up and remove the drivers side wheel:
Then you need to remove/put aside the power steering pump. To do this you remove the trim at the front of the wheel arch:
Then you locate the automatic belt tensioner. Keeping a 5mm Allen key handy (or any other rod of solid metal that is 5mm), you place a 14mm spanner on the belt tensioner and apply pressure in the anti-clockwise direction. This is spring loaded and you will need a bit of pressure on the spanner. Once you have turned it, you will see that the hole at the bottom will line up with a gap in the engine block. You insert the Allen key here to lock it in place:
You then proceed to take the belt off the power steering pump and then unbolting it, putting it to the side to give you some room:
You should then remove the timing gear cover as shown in the PDF above. Removing this is easiest from the top of the engine using an offset ring spanner and small hands. If you don't have small hands, this step will be REALLY difficult.
The timing cover was another little obstacle along the way. Everything about this whole procedure had to be difficult. Some genius thought it would be a good idea to clip one part of the wiring loom to the top of the timing cover. The issue presented here is that it is near impossible to unclip the cable loom, let alone fit a pair of cutters into the engine bay up to that point to be able to cut the cable tie. On top of that, the loom is so restrictive that you can't pull the timing cover up far enough to give you easier access to the clip. After about 5-10 minutes of frustration, I finally managed to cut the cable tie.
Then it's out with the old, in with the new:
Afterwards, you just reverse the procedure. Changing the pipe over is pretty straight forward. It doesn't really take a genius, but it requires a lot of thought on how you will get the tools in there to remove the nuts and bolts. Everything is really cramped inside the engine bay and this is what makes it really difficult.
Would I ever try this again?
... Not for a long time.