How difficult is it to graduate from NYU STERN in 3 years?

Due to finance reason, a student would like to graduate from Nyu stern in 3 years (possibly + 1 summer session)

He will have about 5 6 ap courses with scores of 4 or five

I think that it would be a far better plan to attend a less expensive university.

Expecting to graduate in 3 years is IMHO a rather risky plan.

As long as those AP classes meet requirements and needed electives, it is possible to graduate in 3 years and one summer. It will require 18 credit terms if you want to shoot for it without summers. But since there might be some issues with scheduling conflicts, a summer semester might be necessary.