Im crazy to play this game, but i dont know how and where to install this!
someone help my plzzzz!!!!

There are links in the forums that can help you find and download this game. Now where to install it is up to you.

Link to the downloads section:

http://www.ragnarokbattle.com/forum/index.php?showforum=38

Just search trough there to find a link to download the file then install it.

Here's the download link: http://www.megaupload.com/?f=UJDFYEUX

and here's the guide that our beloved mod kaizer has devoted so much to make: http://www.ragnarokbattle.com/forum/index.php?showtopic=5763
so please read it if you have trouble with installing and such, for his sake