How do we convince my 89 yr old mother it is time to sell her house and downsize to a safer, more manageable environment?

I'm the youngest of 8 children, 6 brothers and a sister. Six of us kids are responsible adults, have families of our own and are not a burden to mom in the least. Two brothers have been nothing but a burden to her, partly because she has enabled it their whole lives, which she continues to this day and blames herself for their behavior. They are 59 and 60 yrs old. Dad passed away in 2016, he was mentally abusive to my mom and they didn't interact much but were married for 64 years. She is in pretty good shape health wise but she is forgetful at times and its getting worse for sure, she will tell you that. She has a car but really isn't doing much driving, grocery store maybe once a week and its fine. When Dad died, brother #5 (60 yr old) saw it as an opportunity to move in with Mom, under the guise of "helping to take care of her", in the house where she raised her family and has lived for 65 years. This brother is nothing but trouble, he grows marijuana on her property, has it hanging all of her barn drying it out, sells it out of her house. Though it is legal in MA, I'm pretty sure what he is doing is NOT! She acts like she doesn't know what he is doing and puts her head in the sand, again she blames herself. He is putting her in danger with his behavior. He pays for nothing, she pays for his car, car insurance, gas, phone bill, and food. He pays zero in rent and you have to twist his arm to get him to mow the lawn. He gets a monthly disability check but of course can work under the table just to game the system. No one knows what he does with his money, though we all guess drugs. He takes her debit card and fills drug dealers car with gas for free drugs, we just discovered this. And if that is not bad enough, he has basically turned into Dad, the way he treats and disrespects her. He is basically a squatter who she won't kick out. She is embarrassed by the whole thing and would rather none of us knew exactly what has been going on. He needs to go, she wants him gone but won't kick him out on the street. The only way she will get rid of him is the sell that house and go somewhere where he can't be. But she is pretty dead set on not going to assisted living or even independent living, nor does she really need it at this point, though probably only a matter of time. She is becoming increasingly depressed and says she would rather slit her wrist than to continue this, she can't take it anymore. She is financially well off for an 89 yr old woman, she has many options and lots of support from the other kids if she will accept the help. But the first step is to convince her to get out of that house, it would not be safe for her alone, if he were to leave. One day she wants to sell, the next day she acts like we're crazy to even bring up the subject. We all just want her to be safe, comfortable, keep her independence for as long as possible and live out her final years without the burden of this parasite living off of its host (her). If we threw him out, she would let him back in 5 minutes after we leave.

I'm on my way there tomorrow for the holidays and a few of us are going to try to get the ball rolling.....any advice how to best go about this??