noun
Polite noun for changing clothes, often used in service contexts or formal situations. The verb form is 召し替える.
お客様、お召し替えの際はこちらをご利用ください。
Please use this room when you change your clothes, sir/madam.
旅館に着いて、まずお召し替えを済ませた。
After arriving at the inn, I first changed my clothes.
着替え is the standard neutral word for changing clothes. 召し替え is a polite, often honorific, alternative used mainly in formal or service settings.
Compound of 召し (honorific prefix from 召す, 'to wear') and 替え (from 替える, 'to change').