I am planning on 20% down , then a fixed payment based on current typical rates for the next 5 years, then a balloon payout at the five year mark.  

I would call them and send certified letter signature required or if nearby drive to their last known address.

i can't legally kick her out, unless she keep paying later after attorney letter, but she stoped after she received the letter

I figured as much since you had a bunch of question marks and exclamation marks in there and a few incredulous capital letters :) .

It got pretty rough for them complaints to the DA the AG lawyer letters etc.. thats about when i met them.

If you had 10 years left on the current note and the 5 year balloon hit. 

Quote from @Eli Ling: also does FO letter mean F@#k off letter?

They make a down payment, set up monthly payments to you and structure it as you feel comfortable with a balloon to fully buy you out. 

Quote from @Kar Sun: My tenant's lease is coming to a close and I am relieved she will be moving soon.She has been paying on time but has been extremely unpleasant and rude.While the money does not smell my mental sanity is more important than money in this case.She sent me a registered letter stating that she feels "unsafe because we have not done the fixes the way she wanted it".She requests to have her witness for a walkthrough.In my state a walkthrough is required but I am not about to grant it to her to bring any witnesses as that is not in my contract.If she feels unsafe she does not have t be present.I also do not treat a final walkthrough with a tenant as a final sign off.This walkthrough does not include a detailed inspection of the plumbing and the appliances that will be done after she departs.This is simply for the visible cosmetic issues and should take less than 1 hr.  

Have gloves and masks for the men , you dont know whats inside Send them a letter telling the residents that on DEC 12 they will be evicted and all their belongings will be put on the curb .