To view it in full screen mode, start the video. Some devices have a full screen option. If yours doesn’t, choose the box at the bottom right corner of the video window and click in the square section. It looks like this 
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Just to forewarn you, there is one period of difficult sound in the first hymn and a short period of silence at the start of the second Bible reading. Apart from that it should work fine, so please persevere!