How to install skins?
 

its a basic question, i do no know how to intall skins to Vbulletin. If some one could tell me how that would be very cool.

Sure. In Admin CP, go to Styles & Templates --> Download/Upload Styles --> Import Style XML File. Find the Style XML, create a new style and add a title. Once imported to activate the style go to vBulletin Options --> Styles & Languages. There you can set the global style. To have custom styles per forum go to your Forum Settings and choose the style you want for specified forums.

I hope that helps. :)