Astra Y reg. estate, boot unlocking problem.

A friend of mine has a problem with the unlocking of his boot. We had
a look at it today and what happens is this:- When he uses the
remote button all the door locks lock and the boot too, when he tries
to unlock, all the doors unlock, but the boot does not. It is possible
to unlock the boot with the key but it is difficult and when looking
at what happens the actuator always operates OK but although the
plastic assembly behind the boot key turns a bit, this motion is not
being sent to release the catch for the boot. It is hard to see how
it is supposed to operate as it is a plastic cylinder affair with a
lot of little bits that might or might not be worn or broken.

What is this bit called and is it possible to mend it if we take it
out to try and see what is wrong? Does anyone know the part number of
the bit concerned and how much it might cost? (It might be a common
fault and have a well known fix.)

Any information welcome. Thanks a lot.

Regards George.
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