This is a tricky procedure and has to be done with the fingers of one hand.
Small hands and dexterity helps. Like most of electrical connectors, it has a lock that has to be pressed in on one side before the connector is pulled apart. There is a small metal tab holding some of the wire to the radiator fan frame - pulling the wire out from this tab will give you some more leeway to help disconnect this connector.
If the horns are mounted on the front horn tabs in front of the radiator, disconnect and remove them.