This video will show you how to manually update WordPress. Links from the video below.
Official WordPress instructions can be found here:
Short version: https://wordpress.org/support/article/updating-wordpress/#manual-update
Long version: https://wordpress.org/support/article/upgrading-wordpress-extended-instructions/
Latest version of WordPress can be found here:
If you need to disable Plugins but are unable to access your admin area, use the detailed instructions here:
Instructions on FTP for Fasthosts customers: