Just a tip for removal WITH your wiper removal tool... If you put the nut back on upside down after removing the washer nozzle jet from the centre of the outlet (just pulls out) Then you can use a wiper removal tool to prise the wiper arm from the spline. The nut protects the end of the thread as you tighten against it.
I have the exact same problem, the little metal tube inside the motor snaped so the washer liquid goes inside the motor and flows inside your boot door. You have to replace the motor to fix the issue. I'm in the process of replacing it now.
