There is noway I can access the broken place behind the firewall at the location X, the plastic part under the wiper motor is one piece completely extends from fender to fender (from A to B in the picture); besides at the far right end there is a rivet R (not a screw) holding it down.
In the schematic below the break is between B1 and B2 and is at the firewall windshield side, while E is the other hose.
The part I need would be D+B (one part, some kind of Y connector), but the problem is how to access it.