Changing Instrument in only one section/movement

Hello I am transcribing a work of multiple movements for wind quintet. I understand how to go into stave properties and change instruments from say a Bb clarinet to an A clarinet. The problem is that I would like to use different clarinets for different movements and when I go to change from Bb to A it changes the clarinet line in the entire score, not just the section/movement that I would like to change. Is there some way to change the instrument and only have it change in one section/movement?