Sorry I couldn't get back on this one but I have been in hospital.
After the reply about going in through the boot trim I discovered the following.
Remove the trim over the rear off-side light cluster and this will expose some inner compartments which are sealed with foam inserts which you can remove easily.
Once the foam inserts are out of the way you can look inside and you will see the small box which houses the mechanism. see photo 1.
The 'ring-pull' on the back end if it should allow you to extract the pin from the filler cap, however, as was the case with mine, this had snapped off inside (see photo 2) and I had to remove the whole unit to get the filler cap released.
That was the next problem, how to remove the unit?
There are no clips / brackets visible so I turned the unit and found that a single nut holds it in place ( you may just see the threaded end - at opposite end to the ring pull).
Once I had removed the unit, the nut fell to the ground from behind the plastic wheel arch inner. I haven't yet been underneath to see how it will go back!!
I have tried glueing the snapped 'ring-pull' end onto the wormed shaft, but it wasn't strong enough and snapped off.
I will try something stronger.
With being in hospital I haven't yet enquired as to a replacement part, but I suspect that it may be a complete unit.
The motor closes the wormed shaft with quite a speed / force and I can see why it has snapped. Probably needs a design change!
Anyway, that's the unit removed and at least I can get fuel in the vehicle. Just need to be careful where I park it as the fuel filler is not secure.
Hope this helps. Plesae feel free to contact me again if you have any more questions.
Had exactly this happen to mine today.
It's been making a horrible grinding noise for a week so I guessed it was on its way out.
Accessing the unit is easy (when you know how)
It goes through the wheel arch bulk head. The main unit is accessed via the cover for the rear light cluster in the boot.
The single nut that goes on the other side of the bulk head is accessible after removing the rear wheel arch liner.
Jack up car; remove wheel; support it; remove liner (two bolts, three screws and two platic plugs.
Bolt is then in easy reach.
Of course with Renaults nothing is simple. One of the studs for securing the liner sheered off in the process of removal.
Had to remove internal trims and drill out the old stud to replace it.
About the fault; I can't see an easy way to fix it. There is a lot of force from the geared motor at this point. Glue just won't hack it. There is a small rubber buffer fitted just behind the point that it sheers and although this probably absorbs some of the shock, after time the plastic gives up.
Anyone fixed one of these?