着替え (kigae) means “change of clothes”

More examples

雨にぬれたときの着替えを、車に積んでおきます。ame ni nu re ta to ki no ki ga e o kuruma ni tsu n de o ki ma su

I keep a change of clothes in the car in case I get wet in the rain.

Describes replacing the clothes on the body with another set, as well as the set used for that replacement.

着ている衣服を脱いで別の衣服を着ること。また、着替えるために用意する衣服。ki te i ru i fuku o nu i de betsu no i fuku o ki ru ko to ma ta ki ga e ru ta me ni yō i su ru i fuku

着替え (kigae) is the noun form of 着替える (kigaeru), which combines 着る (kiru, "wear") with 替える (kaeru, "change").

In travel English, a change of clothes means another outfit, but changing clothes means the act, and Japanese 着替え (kigae) can cover both.