Install it via plugins
then add the following code into a .htaccess file in your www or public_html folder:
# BEGIN litespeed noabortOnce done log back into your Wordpress Dashboard and run a full wordfence scan. If it finds anything you can choose to restore the original which should resolve the issue.
RewriteRule .* - [E=noabort:1]
# END litespeed noabort
Basically select Select Bulk Repair files and Repair them.
For those that cannot be repaired check that the files are not criticial ones and do a Bulk Delete if necessary.
Note: Always make backup of your files before making changes. Recommended.
Lastly open up PHPmyAdmin and check your wp_users table and check if there is any user called Service. Delete this user. At times some users are created as a backdoor for Hackers aswell.