When installing Sytist, you have the option on what to name the admin folder. If you want to rename it after the installation.
1) Download the sy-config.php file from your Sytist installation and open it in a text editor like notepad (Or you can edit it through the file manager in your hosting control panel).
2) Look for the line : $setup['manage_folder'] = "sy-admin";
Change "sy-admin" to the name you want the folder to be ... "my-admin-folder-name". Save and re-upload.
3) Through your FTP program navigate to where you see your admin folder and select rename (right click on the folder) and rename it to the name you entered in your sy-config.php file .... my-admin-folder-name