User Serviceable Parts

Years ago I completely disassembled a .45 automatic and then reassembled it, fired it, and was pleased to see that afterward my hand was not blown off my arm. Hey, I must have done it right! And right now I'm typing on my laptop, in which I just installed a RAM upgrade. It now has more RAM than the desktop I've had for three years. And it works! Phew! It's one thing to blow off your hand, what with the range of prostheses available and so forth, but if I'd messed up my laptop with some bonehead slipup I'd have to spend a bunch of cash for a new one and that would be very inconvenient.