I don't have experience of this, however there is information here https://www.alzheimers.org.uk/get-suppo ... -diagnosis
that you may find useful.
Those on the forum with experience of caring for someone with dementia (any kind) have learnt and advise it's better to go along with the person's experience of reality. So, if they believe they are ok, just a bit forgetful etc then go along with it. The strategies that work in the earlier stages of dementia, can still be implemented and will still work just the same.
If their denial is putting them in danger, e.g. going out alone when no longer safe to do so, then creative strategies will need to be put in place, to ensure they are accompanied etc
If you tell us more, we can tailor the advise more specifically.