I've had to redo the repair I paid the #$%@#% dealer (355 Toyota/Volvo in Rockville, MD) to do. The dealer shop/mech had simply slapped on some copper-colored high temp selicone goo that fixed the leak for three months (You can do this if you clean the area real good...no guarantees how long it will last!).

It took about 15 minutes to get under the car and remove the two bolts that hold the tube to the bottom of the turbo and winkle the tube out of the block...I don't remember if I had to remove the oil filter or not but if I did I probably threw on a new one for GP. It took another ten minutes or so to get the new seals and (old) tube back in place and buttoned up...I used blue loctite on the turbo bolts and torqued them according to the service manual. IMHO, it's no worse a job than changing oil (the real problem is getting to the oil filter) on a 7xx, just takes a little longer.

The O ring and turbo gasket are about $5.

When I removed my tube I found a mostly disintegrated O-ring and an old gasket at the turbo...the dealer had obviously cut corners and NOT installed the gasket/O-ring. I put the parts in a baggie and went back to the service department and, to their credit, they refunded/credited my money.