cron - How to remove this cronjob in ubuntu -

i'm running webserver plesk , installed extension 'kernel care' later on deleted. however, installed cronjob sends me mail every 4 hours:

cron <root@server> /usr/bin/kcarectl --auto-update unknown kernel (ubuntu 3.13.0-042stab123.9)

i ssh server , run crontab -l root but don't see specific cronjob. however, in /etc/cron.d there file kcare-cron , if cat file shows

16 */4  * * * root /usr/bin/kcarectl --auto-update

so thats 1 want delete. can delete file kcare-cron?

type below command in terminal:

contab -e

then comment line # @ start of line below:

#16 */4  * * * root /usr/bin/kcarectl --auto-update

or if want delete can delete line.

on saving file automatically use changes in crontab.

ANy