My dad has dimentia but still knows names, where he is, and drives, although he is forgetful and has a hard time retaining information. My mother-in-law is ready for assisted living but he wants to stay in his spacious home. She has been trying to get him declared medically incompetent and we have been told she did accomplish this. My brother and his wife just came into town and made a plan with the mother-in-law to find an assisted living home and without telling dad just bringing him there when it is ready, dropping him off and just saying you live here now. They will also take away his vehicle at this time. Is this the proper way to handle this?
Is it your step-mother (your dad's wife?) who is working with your brother on this matter? Does she have durable power of attorney?
I think that when your father is told of this move depends on his degree of cognitive impairment. If he doesn't remember things he is told and would have to be told it over and over, upsetting him each time, then putting off telling him until the event is ready to happen may be a kindness.
The "proper" way to handle this is whatever works for a particular situation. It needs to be based on the particular individual involved.
I hope this works out well for everyone.