Here are two pics from my former 01 X5. The supply line is just above the water pump pulley. I just unscrewed the plug that was in the manifold and screwed in the 90 degree brass fitting. At the bottom of the second pic you can just barely see the Y of the return as it enters the raw water intake hose.
2005 X2, Viper Red, MCX, OJ TZ-X5 prop, PPass, rear 750 sacs, KBS, IBS, Bennett Wake Plate, custom wake shaper
(previous) 2001 X5, 1991 TriStar 190