If I get guardianship, how do I actually make an able bodied person accept home care or go to assisted living?

I'm not a lawyer, just a paralegal dealing 70% of my work time in guardianship, conservatorship, trusts and POAs. With that disclaimer out of the way... once you have a guardianship/conservatorship in place, the court will provide you the powers you have for your LO's well-being. If it's not in the order, you can go before the court with your plan/intent, and the court will consider it and issue an order allowing you to move forward to place your LO. The issue of making that transition, of course, and its fallout, will still fall on you. But knowing you have the full support of the court might help you deal with the emotional fallout.