Problem is that when pressing the trigger the line will just run out around the outer spool.

First steps are to cut the mangled lines and remove the bump button and the inner spool.

Pushing down on the white plunger and using a small screwdriver we can remove the e-clip:

We can then remove the plunger and the spring. A retainer can then be removed using a small snap ring plier (thin tips) and the slider can come out.

In our case the slider is damaged, the tab that runs against the spring is broken.

And we can see that one spring is missing:

Replacing the slider with a new one and adding the missing spring fixes the problem.