topbox
What stanley said, plus the little hole to slot the wire into is located on the right side of the barrel.
If you imagine a 'V' shape slot on the right side of the barrel housing,(not on the lock barrel itself but the plastic housing that it slots into) , with the point of the V nearest the outer edge of the box , the little wire slots into a tiny tiny hole, approx 1mm at the pointy end of the 'V' and only needs very slight pressure to push the wafer inwards at which point the key and lock fly out onto the garage floor and scatter the wafers and tiny springs everywhere. Don't ask me how I know

Unless you have three hands- one for the wire, one for the torch and one to catch the lock and key, the weight of the key seems to do a good job of pulling the barrel out once you release it.
The key needs to be inserted into the lock in the locked position.
I think the dealer can do it for you, or it's possible to dismantle the box completely to gain easy access to the barrel from the inside. Pity you don't live a bit nearer, could have done it for you.
I think Ebbo's guide disappeared for some reason- I looked for it a while ago, before learning the hard way, and couldn't find it.