I set up a training plan with Plan Builder that runs from July 5th, 2021 to July 3rd, 2022 (no races), now I would like to shorten the plan and create a new 12-month plan for December 2021 till December 2022.
I can’t find an option to shorten the existing plan, just one option to delete the entire plan, do you have any ideas?
Delete and re-build! ‘Shortening’ it would change all our workouts and the progressions leading into your event in the same way that just deleting and creating a new plan would. Cheers! 
it looks like i found a trick, i haven’t used a Race Date before, so now i added a A-Race on the date i want to end my old Plan and start the new plan, so everything will be adapt by AT and all workouts are gone after A-Race 