Can you change just the blade in windshield wiper on a Nissan Maxima?

I'm going with the assumption that this question is asking about what are commonly called the rubber blade refill inserts rather than the wiper blade which is everything attached to the wiper arm; blade and frame.

Most likely yes - you can just replace the rubber insert however in most cases I don't recommend it, especially if you live in cold winter weather climates which puts a lot of stress on the entire wiper blade or you live in a climate where you use your wipers quite a bit. The difference in price, mechanical skill (and patience) between installing refill inserts and full wiper blades is relatively small. If you replace the whole wiper blade, its cheap insurance that your blades will perform better when you most need them.