Remove mysql 5.6.26-community
To uninstall all files/packages installed by the shell script simply undo all commands executed in the script logged in with an admin account:


Open System Preferences -> MySQL and stop the service if it's running
Open the folder /Applications and drag SequelPro - if it was installed - to your trash.
Open Terminal and enter sudo rm -R /usr/local/mysql-5.6.26-osx10.8-x86_64 to remove the mysql folder
Enter sudo rm /usr/local/mysql to remove the soft link
Enter cd /Library/LaunchDaemons &amp;&amp; ls
Search for the *.mysql.plist (the launch daemon plist of mysql) and remove it with sudo rm com.oracle.oss.mysql.mysqld.plist.
Remove the my.cnf file with sudo rm /etc/my.cnf
Remove the mysql socket soft link and the superior folder with sudo rm -R /var/mysql
Remove all installed mysql package receipts with sudo pkgutil --forget package-id.
Example: sudo pkgutil --forget com.mysql.launchd The name of the other two packages are com.mysql.mysql and com.mysql.prefpane
Remove the file MySQL.prefPane in /Library/PreferencePanes/
Finally cd to /usr/local/bin and check the existence as well as the creation/modification date of the file pidof. Remove it if both dates match with the installation date of mysql.




Addendum

To remove the MySQL installation from System Info -> Software -> Installations (which is a "cosmetic problem" only) remove the MySQL dict entry:

&lt;dict&gt;
    &lt;key&gt;date&lt;/key&gt;
    &lt;date&gt;2015-10-13T15:06:35Z&lt;/date&gt;
    &lt;key&gt;displayName&lt;/key&gt;
    &lt;string&gt;MySQL 5.6.26-community&lt;/string&gt;
    &lt;key&gt;displayVersion&lt;/key&gt;
    &lt;string&gt;&lt;/string&gt;
    &lt;key&gt;packageIdentifiers&lt;/key&gt;
    &lt;array&gt;
        &lt;string&gt;com.mysql.mysql&lt;/string&gt;
        &lt;string&gt;com.mysql.prefpane&lt;/string&gt;
        &lt;string&gt;com.mysql.launchd&lt;/string&gt;
    &lt;/array&gt;
    &lt;key&gt;processName&lt;/key&gt;
    &lt;string&gt;installer&lt;/string&gt;
&lt;/dict&gt;


by editing the file InstallHistory.plist in /Library/Receipts/ with sudo nano /Library/Receipts/InstallHistory.plist or with TextWrangler.