Minecraft Skin Editor is a standalone application that works instantly. You can just upload all your files to the server and it works right away. All you need to do in index.html is replace the domain name with yours and that's it. Installing in Wordpress is child's play. You put the "roseskins" folder into the main directory, that is "public_html", and you paste the code from the index.html file on any Wordpress page in the "custom html" block.