What a weird desire and dilemma. Just make your plan, go talk to the neighbors, give them a range of time it needs to happen in, outline their participation and give them choices of action where the most desirable for you just happens to be in their own best interest as well. And if they still choose to be obnoxious and uncooperative then choose to do the work when they are away and just go switch off their well / pressure, sever and cap the lines, and switch things back on.
And do the severing right at the property line.
And better yet, if they are renters / not their property, then screw all of their petty concerns and deal directly with the property owner and get the job done.