Porsche Babblers - Changing your Boxster's Oil

Required Parts & Tools

Suitable container for catching the draining oil (Blitz makes a seal-able 10-qt. so you may conveniently dispose of your used oil).
An inexpensive general purpose drain pan.
Torque wrench that reads 18 LB/ft and 37 LB/ft.
8 mm Allen bit for socket/torque wrench.
Oil filter cap wrench (Porsche tool 9204 - 000.721.920.40 - or equivalent from an auto parts store).
Oil filter cartridge and O-ring.
Oil drain plug crush ring - in an emergency you may reuse the existing one but the torque setting won't be accurate.

Getting down to business

Make sure your engine oil is warm and not hot as you may burn yourself on the oil or other hot component.
Make sure your car is reasonably level in order to remove as much of the old oil as possible.
You may raise and level the car using jack-stands though it's not necessary if your oil container is short enough.

Most of the following is best performed by laying on your back along the driver's side of the car with your feet pointing to the front of the car and your head just forward of the rear tire. The only limitation with this arrangement is that you can only use your right hand/arm.

Slide the container under the car and position it under the drain plug.
Make sure the relief valve on the drain pan is open or the pan may overflow.
Move the container just enough for you to reach the drain plug with your 8 mm wrench.
Slightly loosen - but do not remove - the oil drain plug.
Slide the oil change container around so that the drain container is now under the drain plug.
Carefully remove the plug. If you let it drop into the pan be sure it doesn't block the drain hole.
Let the oil drain... this will take a while so be patient.
When draining is complete, about 10-20 minutes, slide the oil change container out from under the car. Remember that the recessed area of the container has a little oil in it, and the drain plug, so don't make a mess!
Slide the inexpensive drain pan under the oil filter and unscrew it using the oil filter wrench. Once removed, put it in the drain pan.
Remove the paper element if it's still attached to the car and drop it into the drain pan as well.
Once the dripping has stopped remove the drain pan and wipe around the filter area using a clean rag.
Put the new crush ring on the cleaned drain plug (that you've retrieved from the container) and put the plug back in hand tight.
Torque the drain plug to 37 LB/Ft.
Push the new filter element into place on the engine - there will be some resistance but it will pop on.
Remove the old O-ring from the oil filter cap, taking note of where it's positioned, and wipe up the cap with a clean rag.
Coat the new O-ring with a little motor oil and, taking care, install it onto the oil filter cap.
Install the cap, and tighten to 18 LB/Ft.
Put 8.75 liters of Mobile 1 0W-40 (or your preferred weight based on your specific needs) motor oil into the rear trunk oil fill area.
Wait a few minutes and then turn the ignition on without starting the car and take an oil reading.
If the level is OK then start the car and inspect for leaks.
If all is OK, go driving. :D

Wrapping things up

Take the used oil back to Kragen or some other location that recyles used motor oil. If you used a seal-able Blitz container this is pretty easy. Otherwise you can try to purchase your oil in 5 qt. containers instead of the usual 1 qt. size.

That's pretty much it. Total cost will vary a bit based on your location but will run about $65-$75 or so for oil and parts. If you need to buy tools or other stuff to do it the first time then your cost will be a bit higher but still a lot less than $180 or so most dealers charge.