The old pins were firmly stuck in their brackets - 'seized' as engineers called it - so getting them out was going to need a bit of cunning.
First step was to create a way to get a good grip on the pin and apply some force. We cut deep grooves in the pin, and made a metal collar that fitted into the groove. The collar was attached to a metal frame (called a 'jig') that braced against the side of the lock at one end and attached to a hydraulic jack at the other.
