New User register username with part of email address

Hi,

I’m trying to remove the username field from the default wordpress registration form and have it automated to set the username by email address only up to the @. EG: If email entered is [email protected] then the username would be set to new_user (add 1 if already taken). This is exactly how woocommerce creates my users on checkout and I’d like to copy this functionality across to the registration form. I’ve found the code in the woocommerce file wc-user-functions.php but I’m not sure what to change / copy for my functions.php. Any help much appreciated! Cheers.