how do i upload the skins

You can`t with the demo. Uploading your skins can only be done when you`ve bought a license. You can view them as a demo user, just not upload your own.

Sorry, but it`s not allowed anymore. You`ll need to purchase a license before you can have skins uploaded.

Quote from unseen :

Sorry, but it's not allowed, period. You'll need to purchase a license before you can upload skins yourself.

fixed that for you.

PS: that skin is fugly. hideously fugly.