An uninstall script is included with the installer, you can download the installer and extract it without running it by passing –noexec to it. to download the installer extract it then run the uninstall, use the following commands:

wget http://download.ndchost.com/watchmysql/latest-watchmysql
sh latest-watchmysql
/var/cpanel/addons/watchmysql/bin/uninstall
rm -f latest-watchmysql