angel052274 said

Every time I log on I'm remind to update my plug-ins but I have an older version MAC Book. It have served me well and have no intention of getting other Mac book. How can I update Firefox with an older version MAC? Or at least stop the reminders.

Firefox 16 is the last version of Firefox that works with Mac OS X 10.5 (Leopard). Using a older version of Firefox causes serious security risk. So I'm afraid that there is no way to turn off these security reminders.

"How to update plug-ins with an old MAC?"

Firefox doesn't "update" plugins, that is done either thru the program that originally installed the plugin that Firefox uses, or via the operating system repository that originally installed the plugin - in the case of Linux OS's.

Quite honestly, with that older Operating System and that old version of Firefox - good luck finding compatible plugins that will "pass muster" for "security". Support probably ended some time ago.