This car is up on a lift so the view is a little better than in the garage. The blue out line is the black plastic bottom cover plate, it protects the A/C lines, the bottom of the radiator, and helps direct air. The two yellow arrow are pointing to the ends that are held with 10mm bolts or 25mm TORX one on each side. Right where the blue arrow is a plastic tab that hooks to the bottom of the radiator, just push forward and down. Once you have the end bolts out just pull down and back.

You can look at the post for the turbo return line repair on the FWD cars to get a better idea of what the brace that holds the two pipes together, because on the AWD you can't really see the bracket you have to take off. It is held in place by a 10mm bolt and nut. I reach up over the front differential from the passenger side with a ¼ drive and work the nut loose. When you go to actually put the turbo oil return line back in make sure the old "O" ring is out, and a little lube will help you work the new "O" ring in the hole in the block. Put the "O" ring on the pipe then fit it into the hole, make sure you don't pinch it.

Above is an example of the turbo oil return line leaking oil down the back of the engine. The green circle is where the return line enters the block. An "O" ring/sealing ring part number 1397775 begins to not seal and the oil leaks out, runs down and gets blown back on the bottom of the car. The above leak is not bad I have seen much worse. To correct the problem, replace the "O" ring and the green gasket on the other end of the pipe, part number 3514546.

Several people have commented about oil dripping from the drain hole. The picture below shows one of the causes of the problem. If your oil pan looks like the first picture below and is not machined with a smooth surface for the crush washer to seat against, some 400 grit sand paper will smooth out the mating surface. One of the other problems is that the wrong crush washer is being used and, more often than not, is being put on too tight.

The Volvo recommended interval for oil changes is 7500 miles, I would change it with no more than 5000 miles. If the cost of oil is not a problem I would also switch to a good synthetic 10w 30 oil at 5000 miles. The S 80 takes 7.3 quarts of oil, when adding the oil I would put 7 quarts in, start the engine let it run a minute or so, shut it off and then check your level to see if you need to top it off. Remember it is about 1.5 quarts of oil between the two marks on your dip stick. The oil filter used on the S 80 is the cartridge type, to remove the filter, IPD makes the best filter wrench that I've tried, it cost $28 and their part number is MST1275 you can order on the web