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The two leads at the front of the coil go to the two front cylinder plugs. The two at the back go to the rear cylinder. It doesn't matter which is which on a per cylinder basis as they both fire at the same time - but the leads will only fit one way as the shorter one won't reach the plug on the far side anyway.
The shorter of the two goes to the nearer spark plug.
Then the longer one to the further plug.
If you've mixed up all the wires, just use the ones that are the best length for each plug. It really doesn't matter which one as long as they fit and the plugs in the front cylinder are fed from the front of the coil - and vice versa for the rear.
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