How do you wire a 300 watt subwoofer to the stereo of a 98 ford explorer?

I want to add a 300 watt subwoofer to the stereo of a 98 ford explorer to make it sound better?How do you wire a 300 watt subwoofer to the stereo of a 98 ford explorer?well if your not going to change your deck, you will need a amp that accepts a speaker level input and has a built in crossover.