I have an invention idea

1. Patent search, to make sure no one else has thought of it first and it's not in development already. Then submit basic design and apply for patent. This will cost a fortune.
2. Venture capital, get people to fund your brilliant idea to prototype stage, then design and build, then rebuild, then build again until it works. Or abandon it, when it becomes clear that the concept and the practical reality are two different things.
3. Spend 100's of hours of man time researching it's marketability, and hopefully your market research will show a market available and willing to buy a product of that type. Be prepared for it to show that no one wants it.
4. Persuade those same venture capitalists to manufacture your invention, and beg them to let you keep about 5% of the profits in return for the risk they take.
5. Sit back and watch as your life savings either bear fruit in a successful launch, or sit back and watch your future go down the drain.
6. If successful, hope with all your might that the new, improved version that lies just outside your patent parameters that will inevitably launch within a year of your product doesn't catch on, at least until you've made enough money to consider the stress, risk, worry, work and effort, worth it.
7. Enjoy!