Can I remove/replace the water inlet pipe without removing the water pump on a 3.0?

That's a great design, isn't it? If it's the pipe, you'd probably have to pull the intake plenum to replace it. You could probably get to the small bypass o-ring or hose, but the inlet pipe itself.... yeesh. Considering you have to pull the timing chain to remove the water pump, and that inlet pipe o-ring is on the backside of the water pump, it might be easier to pull the intake.

Actually, you can work it out from the transmission side of the engine after removing air intake, battery and tray, exhaust crossover pipe, (comes out and goes back easy w/old gaskets), heater hoses, and lower rad. hose pipe attached to inlet pipe w/o-ring at other end. Yes O-rings on both ends of inlet pipe. Be patient and jiggle out. I actually got it out without actually bending offshoot heater hose pipe attached to water pump inlet pipe. Use mirrors may help. getting back in may be tricky. Do not install O-ring on water pump end of pipe until you get it back through or you may damage it while working back through the valley of motor

Can I get away with detaching just one side of the exhaust crossover pipe, the side closest to the bumper? Or do I need to take the whole thing out to where that mesh flex stuff is? If so, no wonder I’ve been having a hard time getting the inlet pipe out