When you have an idea that would demand any type of effort from anybody to implement (most ideas do), the sooner you get out of the “this-is-the-best-idea-in-the-world-everybody-will-love-it” mindset the better.
Clarify what others have to gain from the implementation. Most ideas do not exist in a vacuum, and so side effects are to be expected. Identify the positive ones and state them clearly to the people who could reap the benefit. Mitigate the negatives.
Bring people onboard before actually presenting the idea to a wider audience. You most likely have some allies (if you don’t, drop the idea). It’s all about finding them and involving them early in the process. Make sure they understand what’s in it for them and how they can contribute to be part of the success.
Praise positive results of ideas that go in different directions. Change is difficult, and it cannot be lead by a fanboy. All ideas have pros and cons. Be honest about the cons in what you want to do, and most of all be outspoken when it comes to good results achieved by what’s been done so far, or could be done with the same resources.
Offer unconditional help. Perhaps you cannot do much to bring the idea to life, surely you can facilitate the work, shield the team from politics and petty discussions, bring more people on board as needed, champion the idea with internal and external stakeholders, reiterate the vision and the reasons why the idea exist in the first place.
You are close to real change.