I want to apply new skins for KMPlayer. Where should I download them and how to add them to the player?
You can add skins using the database from the developers. There is a page where you can download these skins. The skins are in the .ksf file format. If KMPlayer is installed, double-clicking them will also install the skin, then it's a matter of two clicks to activate them through the Interface.
Skins directory: http://forums.kmplayer.com/forums/downloads.php?do=cat&id=2