Girls, can you tell me how to wake up a baby for feeding? The first da…

Girls, can you tell me how to wake up a baby for feeding? The first day was restless, now he's sleeping, maybe he could sleep for 4 hours. Milk is only starting to come in, doctors say to attach him to the breast every 1.5 hours. But how? I wake him up, he takes the breast and falls asleep ? I'll go crazy soon.