It is not too difficult but it depends what do you have in plan. There are some websites that offer fauces service and you just have to register, add funds to account and it can work on it's own. You get the code that you implement into your website and then you have to put ads around it to make money from it. Note that 3rd party faucets will take around 2-3% of money that is deposited for the cost of service.

It is good passive income but don't expect a lot from it. There is a lot of competition around and you will need well ranked website.