Right Tim, the metal clip (5) pops over the plastic bit and slides down the groove in the plastic bit (2) just behind where yours broke. It's a split clip basically and it holds the clutch cable nipple in the clip. In fact, the while clutch "pull" is taken on the metal clip. That it lasts at all is amazing
The pedal end of the clutch cable has a conical, bullet shaped nipple and that pushes up the tube of the clip and as it pushes up, it splays the metal clip and then the metal clip springs behind the nipple and holds it fast.
Now, I found it best to attach the new clip to the pedal on the bench. With reference to my photo of a new clip, you'll see a plastic peg poking out the side. This is the pedal pivot and the peg needs to be gently pressed in with the clip in place on the end of the pedal. I tapped it home using a small plastic-faced mallet.
Offer the pedal back up but don't put the pivot bolt in. Get an assistant to sharply push the other (gearbox) end of the cable inner until the pedal-end nipple clicks home and is held fast by the metal clip. It needs one to hold the pedal steady and the other to give the incable inner quite a sharp push to get the nipple to engage and click in place.
There are myriad methods of clicking the nipple home but that one was the one that worked for me.
When you have the pedal out, it'll all make more sense.
Take care to get the bushes and spring (items 7, 8 and 9) back in the right paces and the spring in the right way.