Essentially, the reason you didn’t have much success opening up an old notebook is that the manufacturers have specifically designed notebooks for compactness, and as such there are a lot of proprietary connectors designed to keep everything together in as small a space as possible. That means a ton of specialized ribbon cables, heat shields, and tiny machine screws that can easily get lost.

In general, the only user-accessible pieces in notebooks are the RAM (generally) and the hard drive (not always). In some older notebooks where the WiFi component was an add-in card, there may be a door on the underside of the notebook. But in general, notebook components are not user-upgradeable, so even if you ARE willing to deal with screws, tiny little plastic tabs and other such things, there may not be much you can do once you get inside.