Block Term store management tool for all users except SharePoint Admins

Hi,

I am the administrator of my companies SharePoint 2013 portal. I have setup global navigation using the Term Store Management Tool. Some users who have contribute permission on site cannot access Site Settings but if they know Term store URL, they can open it and play with the menu system. This is something we cannot allow users to do. Please let me know some way to block the TSMT for all users except the SharePoint Admins.

Thanks in advance.