Pivot without the drama. Nobody needs a ten-slide eulogy for the old plan.

Changing direction is usually the easy part. What drags is the ceremony around it: the long account of why the first idea was reasonable, the defending of something already abandoned. All of that is for your own comfort, and it teaches the group that changing course is a large emotional event. It does not have to be.

When something is not working, say the new plan in two sentences and begin. A short honest line about what you learned is plenty. Save the analysis for later, and let people feel that adjusting is ordinary rather than a crisis.