Landlord Question and Answer Forum

We have tenants that have been in our property for 4 years and have decided to buy a house. I am honestly happy as they do not take care of the property and we constantly butt heads. They plan to close on their new house in October and move out at the end of December (I have no clue why they are waiting that long to move out). Their lease runs through June 2021. I told them they would be responsible for rent until I found another person to take over and they said they understand. Due to the amount of damage I think I might need to take them to court for fees in excess of their security deposit. I am also not very confident they will continue to pay the rent once they leave. My plan was to make a packet of information for them to sign stating we will let them out of the lease if they sign several forms and continue to pay rent. What information should I try to get from them? I was thinking: Employment verification form (In case I need to garnish wages) A copy of the purchase offer on their new house (So I have their new address on file if I need to take them to court) What other info would you try to get from a tennant to prep yourself for legal battle?