maybe you can do that, if do you have a skill in trading.
It is possible, but many time i am trying to earn fix amount from trading, but believe me it is really hard to earn fix wise, yet i suggest try to earn not see it is fix amount or not.
But as you suggest follow step wise, but i think instead of it trading is risky.
It is not possible, you can have a stable income in trading but never a fix income. One of the reason is that, your stocks price is fluctuating. There is always a difference in its min. and max. sell and buy orders. This will only means your earning will never be fixed. If you want fixed earning go find a decent day job. You will have a fix salary that you can get every month.