This is why I get a loan vs. Lease. Leasing is extended rental and not paying down principle. The reason a lease is more affordable is because you are effectively renting the car. The Buyout clause determines the principle that you agree to pay at the end of the lease to take ownership and can be quite different depending on the lease buyout clause: pay market value (which can increase, but usually ends up less), pay a flat fee, or a combination of both. This is, of course, after penalties (mileage over the maximum per year that was agreed upon, damages over wear and tear, etc). I avoid leases because I always end up over the mileage maximums and those penalties add up quickly.
Best advice is have the dealer work it out with the insurance company; it's what you've been paying them for. You shouldn't be on the hook for anything buyout since that is not an option now.