Ok i have seen this forums skin and it is not a free forum: www.millsberryforum.com and i want the skin it has to go on my forum which is: www.millsberryforum.forumakers.com
Now how do i do that? ive tried importing and exporting skins but it doesent work, why is that?

Well, that's obviously a forum from vBulletin - a different forum host. Importing themes only works if the imported file is in .bbtheme format. Hitskin.com has many of those.