My 83 year old mother has dementia. Her doctors say that she can no longer live alone, how do we convince her to go to assisted living?

She was in the hospital with UTI, dehydration, and pneumonia. She has always been tiny, but now barely weighs 90 lbs. She is now in a nursing care/rehab. center. She is not eating much, very weak and now has to wear adult diapers. All her medical advisers feel that she should not live in her home. She has late stage early onset dementia. My father died a year ago. She is a extremely strong-willed person. She wants to return to her home and says that she can take care of herself. She has shown that she does not take care of her health. When she has problems, such as with her dentures, she will not call to make an appt. She hurt her back and was in so much pain, she just stayed in bed, and ate very little. She never called a doctor. When she finally went to the doctor, that was when all the other above-mentioned medical issues were discovered. She was admitted to the hospital. She was overwhelmed with taking care of my father. Every time we tried to get in-home nursing for him, she would get rid of them after 2-3 days. She does not like someone being in her house. Quite honestly, she is very difficult... sometimes extremely nasty. She kicked her PT just because she didn't like her attitude. We need suggestions on how we can convince her to go to assisted living. She is putting up quite a fight when the subject is brought up. What can we do to get her to understand that this is what is best? None of us can take her in .. the doctors feel that with her health issues, she is best off in assist. living. She is a fall risk and the fact that she is so frail and weak, none of us want to put her at risk by bringing her home. Please give us ideas to convince her.