Yes and no. Here's a list of what can and cannot be updated.
What you can change:
Add/remove members-only content.
The name of the membership.
Which email domains are able to sign up.
Any page redirects (after signup, login, or logout).
The setup fee.
Taxes.
What you cannot change:
If the membership is free or paid.
The price.
Billing frequency.
Free trials.
Keywords: edit a live membership, edit a paid membership, edit an active membership, etc.