There were some thoughtful, powerful, and insightful responses. My answer was as follows:
First: It sounds like you know there is going to be resistance and who those people will be. That means you have not solved the whole problem yet. Put in a little more time, find out why they won’t like the change and incorporate that important information into the final solution. Resistance is vital information
when you are in the process of solving a problem. I am not saying to accommodate tantrums. I am saying mine the information as it is a valuable resource.
Second: There are personality types that resist change. It is their basic modality. If this is the case, you must create a clear path from where you are to where you are going (details) and you assure them that it is fair to everyone on the team. Many people need the change to be “safe” and the change to be “fair” for others. If you can provide that framework, you will have less resistance. For the people who hate any and all change (the people who always say, “It SHOULD be done this way. It’s always been done that way…” and they are unmovable) there are techniques to get them to move. Basically, you need to give them a shove to the new SHOULD and let them get comfortable with it. Pick the correct “resistee” and they will move the rest with them to your “safe” or “should” place.
There are always reasons why people resist. If you have not adequately addressed those issues, you will meet resistance. Your initiative will splutter and fade because even the most determined top-down pressure cannot stand against embedded, deep down feet dragging. If people are not excited (or at least resigned) then your initiative will have failure to thrive. There is no magic button. You need to do the whole job first before you expect them to agree.
Hope this helps.