I will replace that I am able to replace them myself. I will be grateful for any answer.
I do not know how to get new fans/blowers. However, from what I understand, replacing the blower is not that simple.
One of the Intel support engineers will have to assist you.
I don't know where you can buy a replacement blower for your NUC however, I think that the replacement is quite easy in your NUC. See this video how to do this: https://www.youtube.com/watch?v=lKBL1-ARzcM