installing plugins

I have downloaded a couple of plugins from expterzzzz.com and i have no clue on how to install them can someone help me.

You have to read the inclosed Readme, install txt files. Mostly you have to modified excisting php files, import sql files to your database... 

Advise: make a backup from all files you have to change!!!!!!  
If you not do that you can be in trouble before you know.