Their is a water leak after rain to floor on left driver side. Now I have corroded wiring. Land Rover want 15,000 to fix
how do I get at it to clean connectors and fix leak ?

 

There's no magic bullet. Just learn about fixing corroded wiring and terminal pins properly (use crimp and heat shrink seal or solder and heat shrink seal connectors), and open things up to access it all. You might want to source some used connectors and or other components depending on what you find.