I have two left hands (and one of them is backwards) and components spontaneously disintegrate when I touch them. I know I'm not capable of building a computer so I bought mine from Tuxedo computers, who sell computers running GNU/Linux. I might be the GNU/Linux whisperer who manages to not have any major issues, but that doesn't correlate with the type of technical aptitude which would let me turn a heap of components into a working machine. I even managed to break a laptop by trying to replace the CMOS battery.

Making any hardware changes whatsoever to a laptop is dramatically more complicated than building a desktop. It very much is just a matter of 1) buying compatible parts (there are websites for this, or if you shop in person they'll be more than happy to help), then 2) matching plug labeled A to socket labeled A.

Hah! You're like one of my family members. We keep her away from anything electronic because the failure rate in her presence can not be accounted for by accident alone.

Oh, and laptops are nasty. They are put together in ways that can easily confound you when you have plenty of experience. Lots of it revolves around little pieces of plastic that are marginal when new and that just want to break by the time the device needs service. It's a conspiracy!

Anyway, at least you know it can be done. The conditional still holds.