Convince ‘em, or fight ‘em. Of course.
What are you going to do to pass this amendment of which you speak, and what will its wording be?
What, you're going to personally go around to their offices and beat them up if they don't get in line?
What are you going to do to pass this amendment of which you speak, and what will its wording be?
Convince them. Wording is subject to consensus.