Few laptops are easy to disassemble even without all the screws. The plastic interlocks, like around the keyboard, almost always get stressed or damaged. My advice if you feel you have to do some preventive fan maintenance, only remove those panels, like the ram cover, that are relatively easy to get at. Then gently blow air reverse-flow through the exhaust port with something like a hair dryer on no-heat, the blower side of a vacuum cleaner, a compressed air keyboard cleaner or even your own lungs. I doubt there's that much dust buildup unless the computer is mostly operated in a very dusty environment. Almost all laptops get quite warm at times of heavy CPU usage, nothing unusual about that.  If it were mine, I wouldn't try to fix something that doesn't seem to be a problem.

Jack E/NJ