Contact a Steering Exec. member and let them know there’s something you’d like to talk about at steering.
Write up a short proposal. Include what you want to accomplish, what your reasoning is, how much it would cost, etc.
Have a conversation with Steering Exec. about your proposal. They will ask questions, make suggestions, put you in touch with other interested people.
When everyone thinks the proposal is fleshed out enough to go to steering, ask to be put on the agenda.
Come to the meeting and share your proposal as a discussion item. Bringing copies of your proposal to pass out is often helpful. Answer questions, consider other options with the group.
When Steering is ready, your proposal may be a decision item on the agenda, often the next month. Come to the meeting, briefly remind steering of the proposal, answer any more questions, and then it can be voted on when the Steering group is ready.