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It'll have an orange rind with orange spikes. Squeeze it slightly to make sure it has some give and isn't rock hard and green. If you can't find a fully ripened fruit at the store, wait for it to turn orange before eating it. While you won't be eating the outside, it's always a good idea to rinse fruit you're planning on cutting, to avoid any pesticides or other chemicals on the outside when you cut into it with a knife. Set one half aside. This is the best way of cutting the fruit for eating it by itself. If you want to scoop the seeds out for use in a recipe or fruit salad, it can be easier to scoop if you cut it lengthwise. It's up to you.
Choose a kiwano that is fully ripened. Give it a rinse. Cut the fruit in half short-ways, across the equator.