I am not sure how to add the plug ins into my morrowind game file or whatever it is called. I know I have to unzip them somehow but I no idea how to get to some Morrowind "directory". So any help please because this stuff is too confusing for me.

Read the http://www.gamesas.com/index.php?/topic/106063-morrowind-mods-faq/page__view__findpost__p__1772641 on how to install mods.