Long time loud fan now quite as a mouse!
I'm an audio engineer and I had for a long time been really bugged by the persistent and burdening murmuring of my laptop. Not knowing a quick fix I searched for the symptoms and was able to isolate the probability of it being a fan... the right fan. Now I needed a solution.
I was thrilled to find ifixit.com's easy step-by-step instructions and parts supply readily available and arrived in two days from order with standard delivery for under $25. The only additional supply I needed to purchase was a hairdryer since I had the hex and mini screwdriver from a previous repair. I'd never removed a logic board before, and I'm working on a machine that's 6 years old so naturally I was a little concerned about playing around with the internals, but the surgery was a blinding success and came in at under 3 hours work. Now I'm back in the studio and fearless of being the background "tone".
Take your time with these repairs, be gentle with your machine and give yourself ample light and a clean workspace.