command: /skin

quick ref:

/skin [@playername] [filename]

description:

change skin. if no filename is specified a random one is used. 
@param playername: if not specified and containing entity is a biped, it is the containing entity like NPC; otherwise it is current player
@param filename: can be relative to world directory, or "Texture/blocks/human/" or root path. It can also be preinstalled id 
/skin 1     :change current player's skin to id=1
/skin texture/blocks/1.png :change current player's skin to a file in current world directory
/skin @test 1:  change 'test' player's skin to id=1

换皮肤命令Skin

例如

/skin texture/blocks/1.png 改变当前人物的皮肤为texture/blocks/1.png