Alternatively, you can just replace your existing Validate.php with the patched copy of this file which you can find here. Rename the existing file /prestashop/classes/Validate.php /prestashop/classes/Validate.old then download this file and rename it to Validate.php and paste it into the same folder.
Once you have added the store locator installation code you can revert back to the original Validate.php file if you like, it's up to you.
3. Click on Design -> Pages and Add new page.
4. When adding the Page Content, ensure you press the <> button to select HTML mode and paste in our embed code.