The side play in the video seems a little excessive but I wouldn't be concerned really. The only possible fix would be a new cam gear and chain and it may not be any better due to the design of the gear.
Looking at the parts microfiche there appears to be a pin the tensioner blade slips over at the bottom and there's a hairpin clip securing it. That means the top of the engine, head and cylinders, has to come off to replace. Looks to be an auto adjust mechanism so there's no manual means.
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