I need to do the same thing.

My 95 850 Turbo has 6 hoses going into it.
The Radiator Hoses are pretty obvious.
I just did a Tranny flush on my mom's V70, so I know that the driver's side upper and lower hoses are the ATF cooler hoses... (When performing this flush, I replaced the clear and green O-Rings as well as the metal fitting - although the metal fitting did not seem like it really needed replacement).
What's left are the Passenger side upper and lower hoses. After reading the Haynes manual, it appears as though these would be the Oil Cooler Hoses??

Questions:

1. Are the upper and lower hoses connected with metal clips on the Passenger side of the radiator in fact Engine Oil Cooler Hoses?
 
 
2. When disconnecting the hoses with metal clips, will fluid completely drain out? (During the Tranny Flush, I had minimal spillage, but that was because I quickly turned the hose up and connected the clear drain tubing. At that, the real drainage occurred with the engine running and pumping fluid, but again, I only had the upper hose disconnected)
 
3. Will I need to drain the Engine Oil? or ATF?

4. Will I need to replace Clear and Green O-Rings and or Metal Clips for each of the 4 connections?