You can update your details via the website or the Coles app.
Website
Step 1: Log in to your account
Step 2: Click on your name
Step 3: Choose the section you need to update, and follow the prompts to edit.
Step 4: Save your changes.
Coles app
Step 1: Log in to your account
Step 2: Tap More
Step 3: Choose the option to manage your account
Step 4: Edit the details you need to update
Step 5: Save your changes.