Making my own dimmable lamps

I would like to get into creating my own lamps using the electronics from old thrifted lamps (inspired by this video).

For an idea I have in mind, I would like the lamp to be dimmable. Assuming the lamps from the thrift store don’t already have a dimmer built in, is it as simple as buying something like this dimmer and replacing the original on/off button with it? If so, how difficult would that be for a complete beginner?

Really new to all this, so any kind advice is appreciated 🙏🏼