You give exams in person, in class, on blue books, no phones. This part isn't hard. Instructors have been doing it for generations. It's only in the post COVID era that some have moved to having exams take home and on Canvas or similar platforms. This is great for instructors -- less work! but I am not convinced it actually helps students.

The part that is more difficult is take-home work, and I think the solution is that instead of being something that you turn in for credit, it needs to move to being more of a chance to practice for in-person exams.

What about essays? I've taught classes where students had to write essays in class, in person. On paper, with a pen (this may no longer be allowed on many campuses because of access and perceived fairness reasons, which IMO is a shame, but it is what it is). I think the traditional assignment of "write a 15 page paper on XYZ" is probably done. Instead students will have to prepare to write an essay in class by reading the source material (books, papers, etc) and converse with AIs that are hopefully not hallucinating, to get an understanding of the material and then come to class and be prepared to write about it.

It's a new world, but one we can adapt to.