The skins you download for rainlendar need to be extracted to their own folder in the skins folder, in the rainlendar directory (C:\Program Files\Rainlendar\Skins). Once there, if Rainy is running, right-click on the calendar and select refresh. This will make the skin show up under the skins menu
Pretty much the same deal with sysmetrix, unless it's a *smx file, on those all you have to do is click on it.
