When you get 404 error page while accessing wp-admin page, you may need to update your site url in the database. Follow the below steps to change your site url from cPanel.
1) Login to your cPanel interface.
2) Click on the icon ‘phpMyAdmin’ from ‘Databases’ section.
3) Select your WordPress database from the phpMyAdmin panel.
4) Go to the table ‘wp_options’ and click on the ‘Browse’ option.
5) Find the option ‘siteurl’ and click on the ‘Edit’ field.
6) Change the URL in the input box of ‘option_value’.
7) Click on the ‘GO’ button.
Then try to access WordPress wp-admin page.
If you need any further assistance please contact our support department.