Once you had set up your Aero Checkout Page and you wish to change the page title which you want to make live for your store, you can update easily by clicking the Pencil icon.
A is Global slug which is appended to all AeroCheckout Pages
B is a local slug which is appended to each checkout page and local to that page.
Now A can be managed from Global Settings
and B can be managed by editing the page
You cannot remove A/ as it technically refers to our post type.
Suggest you can name it as
Or something else which suits you
See the steps below in Action