Within the video below it will show what you can change within a membership plan whilst it is live, as well as other important information to do with changing a live plan.
What can you change?
You can change available payment methods, letting you cancel the current payments and immediately choose the newly added payment.
You can change class access, and this will effect everyone attached to that membership.
What can't you change?
Payment scheduling is immutable once added to a member, to change payment scheduling on a membership the payment must be removed and re-added.
Bolt-Ons cannot be changed once a membership is setup, you must once again remove the membership, and then re-add it ticking the bolt-on this time.