Is there any way to prepare for what comes after becoming a guardian?

I hope soon to become my mother's guardian due to her in a ability to live alone safely. Because of her dementia she has delusions, hallucinations and is paranoid. I have gone from being friend and daughter to caregiver, and now to enemy. Mom is against the guardianship, against all help at home, and against assisted living. It looks as if the guardianship will be final soon. Does anyone have advice as to the aftermath and the actual move to assisted living that I plan? I have picked out the nicest assisted living with memory care that I could find, but of course I understand how this is something my mother doesnt want. This is the saddest decision I have have ever had to make, but I know it is necessary for me and my siblings and for mom. My siblings are supportive of the plan.