Hi Dave
There are two types of locks. I presume you have the earlier version. I am doing this from memory as I don't have a sample with me. Hope its right
There is a hole in the side of the barrel part. You need to turn the key so a brass coloured bump is lined up with the hole. You then use a thin drift or drill bit to depress it and remove the lock. Might need some q20 or similar.
On the same note before you replace the lock soak it in paraffin. Its usually a dirt build up in the lock that stops it working. Otherwise I have also drilled out the rivets and cleaned and assembled with nuts and bolts instead if the rivets. Worked for years
I hope this makes sense
Regards
Allan
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