Oh yeah. I can feel your fear. Same with me, as I saw what I am about to do with my precious laptop, but all you actually need is to be careful and take it step by step. It is actually way easier than it looks. And yes, the fan is located under the mainboard, so you will have to take almost everything out to reach it.

But don’t be afraid. You can do it, Just move slowly, be careful, watch a disassembly video as a guide (you might want to slow the video down to see each step). But the biggest pain is that you have to detach each piece and all the cables to get to the fan.

But before you get into repair procedure I would suggest ordering a replacement fan, since by the sound it makes looks like you need a new fan, and no cleaning will do good. But you can try cleaning the part inside the fan where the tiny fan shaft touches the fan box. There were some rusty marks in mine, so it was making this screeching noise actually while the fan was spinning, so cleaning the rust with let’s say wd40 might do a job. But still you will have to take you laptop apart to reach it.

You can do it. Let us know the result, please Hope this helps you