Alter the CUSTOMERS table to change the primary key to Email to ensure each customer is uniquely identified by their email address.

To alter the CUSTOMERS table and change the primary key to Email, you would follow these steps:

1. First, you need to drop the existing primary key. You can do this with the following SQL command:

ALTER TABLE CUSTOMERS
DROP PRIMARY KEY;

2. After dropping the existing primary key, you can now set the Email column as the new primary key. Use the following SQL command:

ALTER TABLE CUSTOMERS
ADD PRIMARY KEY (Email);

Please note that all email addresses in the Email column must be unique and not null before you can set it as a primary key. If there are any duplicate or null values, you will need to resolve these issues before running the above command.