In this documentation, you'll learn how to change the contact information on a Checkout page.
Here's what we're going to edit:

Here's how:
Step 1: Go to the 'Design' tab in Checkout
Click on 'Edit' to edit the template using the built-in Customizer.

Step 2: Click the pencil icon on the header
On the left-hand side panel, you'll see the option for changing the contact information:

Make the changes as per your requirements.
Step 3: Hit the 'Publish' button

This will save your changes made to the contact information.