Broken electric window

Hi,

My Mum's car (2013) was having trouble with the drivers electric window not working, so I said I'd have a look at it.

When the switch was selected for up and down, we could hear a "crispy" type of noise.

So I took the door card off, and found a rusty broken cable end near the access hole, and when I took off the electric window motor, found a gathering of some more cable. I'm guessing the cable broke at the rusty spot, then when my Mum tried opening the window, it starting pulling the cable into the motor area, with it not being able to carry on the other direction, because it was broken, no tension.

My Mum was saying that the door was leaking a couple of years ago, and had work done to it.

It looks like a tricky enough job to do, access is fairly tight. Can the cable just be replaced and threaded through where it needs to go? Or are other parts needed? The motor runs fine off the door, and the gears that it drives inside the door look ok too.

I also found the part shown in the 3rd picture in the bottom of the door, does anyone know what it's used for? It's about an inch long, plastic, with a metal spring.

Thanks.