Long term tenant refuses to sign a new lease without major changes, that we don't agree with.What should we do

I would think that it is time to give them a notice to move out.

Please describe the problem.

depends on the tenant, is it a nationally accredited tenant whose staying their is the basis of the building's value? Then you may have no choice. In other words, if you need that specific tenant there to maintain building value, perhaps ask for a longer term on the lease in exchange for the major changes. That way you have a chance of selling the building at a price where you can recoup costs.

If you don't have them sign a term lease, check your current lease. It should state that it becomes month-to-month. You can then raise the rent. If they don't like it they will move out. Unless the home is uninhabitable you don't have to improve the property. If they leave, you (well I anyway) would end up spending money to get it back into showing state. Normal "Wear and Tear" needs to be touched up. Sometimes with longer term tenants, that "wear and tear" is "repaint everything". Anyway, I would say if you value your tenant, and they treat your property good. Why not work with them and IMPROVE your property, making them more happy and more eager to stay even longer. They should understand a rent increase if you're doing improvements versus repairs. If not, find someone else who does. Just don't over improve to the point where you can't get your money (rental market won't support price for location)

Check your lease for a holdover clause, if you have one then enforce it. If not, it's time to contact a qualified local broker to represent you. You have to go back to the negotiable table and strike a new deal.