When a plan changes, lead with the information that affects other people. "We are moving the practice session from the park to the community hall" gives the new location immediately. Then add the reason: "The outdoor area is closed for repairs."
Say what remains the same: "The start time is still ten." Without that sentence, listeners may wonder whether the entire arrangement has changed, even if you only meant the location.
Identify the action now needed
Continue, "Please come to the hall's side entrance. You do not need to bring outdoor chairs." These details connect the update to preparation and arrival. Include only changes that actually apply to the event.
If an important detail is unresolved, make that visible: "I am still confirming which room we will use. I will send the room number this evening." Do not hide uncertainty inside a confident announcement or leave people guessing whether a follow-up is coming.
Practice with a partner who heard the original plan but not your reasoning. After your update, ask them where and when they will arrive and what they will bring. Their answer tests whether the new instructions replaced the old ones clearly. A good explanation of change gives enough reason to make sense of the decision while keeping the current practical arrangement easy to find.