The easiest way we know of is to visit Clip Converter and use that free tool to download videos from YouTube.
Another options is a free and totally safe plugin for Firefox that will allow you to download videos from YouTube. We use it all the time.
Once you download the videos you can upload them to your WeddingMix project if you have the web Upload Link add on.
If you do not have the upload link add on option it can be added to your package for $25. Contact us to add this to your package today.