I must admit, I'm real hesitant to open up and mess with my laptop. I've added extra ram, and vacuumed every visible vent, but that's about it.
With my desktop towers, I'm comfortable fooling around. I've added extra hard drives to mini-towers with only room for one. Hacksawed off parts from a heatsink to make them fit.
When the built-in fan on a graphics card fan failed, I got a small fan, plugged it into the motherboard and used velcro to hold it in place. Worked fine.
One time I was fooling around inside a tower with power turned on. A slave drive was plugged in and in my hand. I moved it within the tower, and the corner of the drive touched two prongs in a loose molex plug. The short blew the power supply, but nothing else.
I always turn the power off now.
