Sorry bro, it's next to impossible because everyone uses a lot of proprietary stuff, and you have to 'engineer it' to work. With desktops, sure you can plug the parts together and it'll work, but laptops have so many heat/temp constraints because of the packed parts that it'll probably not work when you finish.
I just swapped out two harddrives between laptops to make use of another's cd-rom drive and even then it was a pain. Harddrives and ram are the easies thing to access in a harddrive and it was a chore in itself. Imagine the other components...