Transition plan
You should work with daycare educators on a transition plan. For example, first two days you stay there until lunch time, then you take your kid go home. The next two days, you stay a little shorter, but pick him up earlier. Always say goodbye to your kid before you leave. Even though he is crying, you should just leave and do not return. But make sure one of the educators will comfort him when you leave. Kids are smart. They will get used to it and enjoy the daycare.