Error Opening the website

Hi i kinda new at wordpress. My site is up and working, yesterday i was messing arround a pluging “FACEBOOK LIKE” and today when i tried to open my website i.e https://www.epiczone.net and wp-admin it says

Warning: Cannot modify header information – headers already sent by (output started at /home/ezone54/public_html/wp-content/plugins/facebook-like/facebooklike.php:424) in /home/ezone54/public_html/wp-includes/pluggable.php on line 897

how should i fix it.
Please help me out