Go to Youtube and find the movie you want to embed

Click on Share


Click on Embed


Change the Video Size

Deselect 'Show suggested videos when the video finish' if it is ticked

Copy the embed code

embed again.PNG

Click on the Edit HTML tab in the blog posting window, click where the movie is going to go

Press Ctrl (Command V)

Click on the Compose tab and you will see the movie in the posting box


You can add a movie file from your computer but I do recommend that you upload your movie to Youtube and then embed it from there, following the above instructions

Click on the Insert movie icon on the toolbar


Click on the Browse button and navigate to where your movie is saved

Double click it and then click Upload


The movie will appear in your blog post and will take some time to convert depending on how big it is