Excellent question, Ms. G
I've found that honesty--but not too much honesty--is important. Adaption to change is a core competency for any student/employee. Therefore when changes occur, I first explain what the change is and then the benefits of the change to them, to me, and to the school. I also ask that my students provide verbal or written feedback to me after a week...then again in a month.
Knowing that they will be giving feedback in the future puts them in a state of reserving full jugment and makes them feel like they are a part of the process. As far as the resistant-to-change students, this gives them an outlet to express themselves.
I think the most important thing to remember is that it is manageable with time, structure, and a written document. Always include that document in their records and if possible have students sign an acknowledgement of receipt.
Lastly, get your dean's input if this is not a campus-wide policy so no one is blind sided.
Hope that helps :)
Taryn Herrera