을 바꾸고

… and change (something)

→ 을

phrase Common #2,320

… and change (something) 을 marks the preceding noun as the object of 바꾸다 (“to change”); 고 connects this action to what follows.

KO: 일정을 바꾸고 싶으면 마음대로 해, 당신 시간이야.

EN: If you want to change the schedule, go ahead—it’s your time.