There is a folder in the zip file, just unzip it. Then drop that folder into the skins folder of Rainlendar2.
c/program files/rainlendar2/skins
Then rightclick on the rainlendar you have on your desktop. Choose refresh. Right click it again, choose options. A window will pop up, click on the 'skins' icon at the top. You will see the new skin in the list. Choose it and hit the 'ok' button.
